7/22/07 - 7/29/07
by C. Zaitz
This year marks the 400th anniversary of the first permanent English settlement in the Americas. Jamestown, Virginia is known as the birthplace of the country, where the first boatload of eager colonists landed. They arrived in May, and I can imagine that the summer was filled with building, hunting, cooking and fending off human and animal enemies. By July I imagine that the colonists were wondering what they had been thinking, coming to a new world so far from home. They must have been hot, hungry, riddled with mosquito bites and maybe a few arrow wounds. But enough of them survived the terrible famines and attacks from the Spanish and Natives to build homes, churches and official buildings, to flourish and become farmers and businessmen.
400 years later, we can wonder what happened to that colonizing spirit. When you first heard that we’d gone to the moon, didn’t you think Mars was next? What happened? Yes, space travel is very dangerous, expensive and time consuming, but was not also crossing the Atlantic to the New World?
Old colonizing risks: Running out of food and water. Disease and pestilence. Getting speared by someone already living there. Death.
New colonizing risks: Running out of food, air and water. Disease and pestilence. Getting lasered by someone already living there. Death.
So why haven’t we planned a mission to Mars? Are the risks any greater? Are the costs heavier? If we really wanted to travel to Mars, we would. America has not been frugal when its will was strong. Why do we not establish a mission to Mars, to walk the rusty sands and build a human presence on that nearby planet? Perhaps we need an outside menace to motivate us. The mission to the moon was a response to immediate threat of Soviet superiority. Without that threat, it’s not obvious that we would have endured the expense and the risk. But being motivated by threat is not the best case scenario, since the threats that would motivate us to travel to other planets usually involves the destruction of our own planet.
But it’s not all gloom and doom. Economic incentive seems to be what drives us today, rather than fear of asteroid collision, irreversible global warming, or even nuclear holocaust. Some say our governments should pool resources and offer incentives to private companies to innovate. Private companies can often get the job done with less bureaucracy, more efficiency, and less waste than governments. That requires widespread cooperation, however, and economic motivation. Companies need to know what they will gain from the endeavor. On the other hand, did the Jamestown colonists really know what they were getting into before they left England? They surely weren’t making a profit during the first years of starvation.
I don’t think our will is weak. We are fascinated by space travel, by UFOs and aliens. Maybe we are just yearning for proof that it can be done. Whatever our ultimate motivation, I hope that it includes our will to survive and our curiosity to know the universe. And I hope we don’t wait too long to get started. Who knows where we’ll be in 400 more years. I hope it doesn’t take a threat of Jupiterian superiority to get us motivated, because by then, it may be too late.
Until next week, my friends, enjoy the view.
Wednesday, July 25, 2007
Tuesday, July 17, 2007
Night Watchmen
7/15/07 - 7/21/07
by C. Zaitz
There are a lot of things floating above us, circling the planet all day long, all night long. While we are all sleeping, there are flocks of satellites gliding silently overhead. If you’ve been out this summer even for ten minutes of star gazing, you’ve seen them. I love it when you can see more than one at a time. They look like a flotilla of space ships, and I imagine a future where they are just commuters coming to and from work.
Meanwhile I looked into what is really up there. Mostly, it’s derelict satellites, parts of old rockets, debris from collisions and even frozen space sewage. It seems the astronauts launch it out into space to get rid of it. Unfortunately, the bags of waste have the same orbit as they do, so it is not unheard of that someone might meet up with it in a future orbit.
There are many different types of orbits for satellites. The International Space Station and most of our weather satellites are in LEO’s, or low earth orbits. They are speeding along at nearly 20,000 mph because they are so “close” to earth, at only 200-500 miles. They circle the earth every 90 minutes. If they went any slower, earth’s gravity would overcome them and they would tumble to earth, burning streaks of incinerated satellite parts as they fell.
A common LEO, especially for satellites that need to see the whole earth over time, is a polar orbit. As the satellite travels from pole to pole, the earth rotates underneath. Over time, the satellite will have passed over the entire planet, just by maintaining its orbit. They can map the entire earth. Remote sensing and long term weather satellites are often in these polar orbits. These are very common to see. I saw three the other night, all at slightly different speeds, but traveling along the same trajectory like silent watchmen.
A GEO is a much higher orbit. GEOs are geosynchronous orbits, meaning they are up so high and going just the right speed so that they appear to be stationary over a certain spot on earth. You can imagine what use these orbits would be, especially if you were curious about a certain spot on earth. Unfortunately, at 22,000 miles up, the view is not as sharp as a lower orbiting satellite's. Their advantage is that they have a large coverage area. We use them for relaying a signal for communication or broadcasting. Our telecommunications satellites are in GEO orbits. The problem with this kind of orbit is that the satellite must be directly over the equator to maintain the orbit. That leaves out the polar regions, and those folks want their satellite TV, just like we do. So we have another orbit, a highly elliptical one, which can come close to earth at one point, even a polar region, and then wander father out.
If you’d like to know exactly when satellites are passing over your head, you can go to the Heavens Above website and enter your town. You’ll be surprised at what you can see. And it’s just the tip of the iceberg of the night watchmen. You’ll be surprised at who’s seeing you!
Until next week, my friends, enjoy the view.
by C. Zaitz
There are a lot of things floating above us, circling the planet all day long, all night long. While we are all sleeping, there are flocks of satellites gliding silently overhead. If you’ve been out this summer even for ten minutes of star gazing, you’ve seen them. I love it when you can see more than one at a time. They look like a flotilla of space ships, and I imagine a future where they are just commuters coming to and from work.
Meanwhile I looked into what is really up there. Mostly, it’s derelict satellites, parts of old rockets, debris from collisions and even frozen space sewage. It seems the astronauts launch it out into space to get rid of it. Unfortunately, the bags of waste have the same orbit as they do, so it is not unheard of that someone might meet up with it in a future orbit.
There are many different types of orbits for satellites. The International Space Station and most of our weather satellites are in LEO’s, or low earth orbits. They are speeding along at nearly 20,000 mph because they are so “close” to earth, at only 200-500 miles. They circle the earth every 90 minutes. If they went any slower, earth’s gravity would overcome them and they would tumble to earth, burning streaks of incinerated satellite parts as they fell.
A common LEO, especially for satellites that need to see the whole earth over time, is a polar orbit. As the satellite travels from pole to pole, the earth rotates underneath. Over time, the satellite will have passed over the entire planet, just by maintaining its orbit. They can map the entire earth. Remote sensing and long term weather satellites are often in these polar orbits. These are very common to see. I saw three the other night, all at slightly different speeds, but traveling along the same trajectory like silent watchmen.
A GEO is a much higher orbit. GEOs are geosynchronous orbits, meaning they are up so high and going just the right speed so that they appear to be stationary over a certain spot on earth. You can imagine what use these orbits would be, especially if you were curious about a certain spot on earth. Unfortunately, at 22,000 miles up, the view is not as sharp as a lower orbiting satellite's. Their advantage is that they have a large coverage area. We use them for relaying a signal for communication or broadcasting. Our telecommunications satellites are in GEO orbits. The problem with this kind of orbit is that the satellite must be directly over the equator to maintain the orbit. That leaves out the polar regions, and those folks want their satellite TV, just like we do. So we have another orbit, a highly elliptical one, which can come close to earth at one point, even a polar region, and then wander father out.
If you’d like to know exactly when satellites are passing over your head, you can go to the Heavens Above website and enter your town. You’ll be surprised at what you can see. And it’s just the tip of the iceberg of the night watchmen. You’ll be surprised at who’s seeing you!
Until next week, my friends, enjoy the view.
Tuesday, July 03, 2007
The Heavens
7/8/07 – 7/14/07
by C. Zaitz
I have a collection of old astronomy books. Sometimes the author will refer to the sky as “the Heavens.” What a lovely way to think of the regions above our heads. It gives the sense of the vastness and beauty of the sky, but the term does tend to lump everything together. “The Heavens” is a more encompassing term than saying the singular “heaven” but it doesn’t truly capture the layered and complex nature of what lies above.
For example, during the day, the sky is all around us, and we rarely ever look at it, just as we rarely look at the ceiling in our house. But the sky is much more interesting, even on a bland day, than the ceiling. The sky has magnificent layers of intrigue, layers of depth and color. Blue skies aren’t just blue, and grey skies are even more colorful. My favorite, of course, is the black sky of night, when all the subtle, distant and concentrated light from the stars can penetrate the atmosphere and be seen here on earth.
But sometimes when you look up, you see what looks like “heaven” from what we’ve seen in paintings and drawings. We can see rays of light coming down from the frothy, fluffy gold-edged clouds with a bright sun lighting them from behind. It’s a beautiful scene, which is probably why it was chosen to represent heaven. Those rays have a technical name. They are called crepuscular rays, which certainly isn’t as poetic a term as “heavenly rays,” but describes the rays of light that seem to spread out from behind back lit clouds, especially at twilight. Crepuscular means, “twilight,” though the effect can happen anytime there are enough particles of dust or vapor in the air to scatter light well. The cause of these rays is a combination of light and shadow. The light is always there when the sun is out, but the shadow created by an object like a cloud that gives the light a “ray” appearance.
From our perspective, the parallel rays from the sun actually look like they diverge from behind the cloud, giving them that spread out “ray from heaven” look, as if a heavenly body shone a great golden flashlight to illuminate our little patch of earth. It’s the same trick of perspective that the brain plays to make parallel railroad tracks look like they converge at a distance.
There certainly are other beautiful effects of light and shadow, scattering and perspective to be seen in the sky, but I think crepuscular rays are some of the most evocative. Perhaps it’s because they do seem to be flooding the earth with golden light, almost like a curtain opening up onto earth’s stage, as directed by something bigger than ourselves. Next time you see them, you’ll know that they are caused by natural circumstances, but you can always let those pretty rays take your gaze up into the sky. I assure you there will always be something interesting to see in “the heavens.”
Until next week, my friends, enjoy the view.
by C. Zaitz
I have a collection of old astronomy books. Sometimes the author will refer to the sky as “the Heavens.” What a lovely way to think of the regions above our heads. It gives the sense of the vastness and beauty of the sky, but the term does tend to lump everything together. “The Heavens” is a more encompassing term than saying the singular “heaven” but it doesn’t truly capture the layered and complex nature of what lies above.
For example, during the day, the sky is all around us, and we rarely ever look at it, just as we rarely look at the ceiling in our house. But the sky is much more interesting, even on a bland day, than the ceiling. The sky has magnificent layers of intrigue, layers of depth and color. Blue skies aren’t just blue, and grey skies are even more colorful. My favorite, of course, is the black sky of night, when all the subtle, distant and concentrated light from the stars can penetrate the atmosphere and be seen here on earth.
But sometimes when you look up, you see what looks like “heaven” from what we’ve seen in paintings and drawings. We can see rays of light coming down from the frothy, fluffy gold-edged clouds with a bright sun lighting them from behind. It’s a beautiful scene, which is probably why it was chosen to represent heaven. Those rays have a technical name. They are called crepuscular rays, which certainly isn’t as poetic a term as “heavenly rays,” but describes the rays of light that seem to spread out from behind back lit clouds, especially at twilight. Crepuscular means, “twilight,” though the effect can happen anytime there are enough particles of dust or vapor in the air to scatter light well. The cause of these rays is a combination of light and shadow. The light is always there when the sun is out, but the shadow created by an object like a cloud that gives the light a “ray” appearance.
From our perspective, the parallel rays from the sun actually look like they diverge from behind the cloud, giving them that spread out “ray from heaven” look, as if a heavenly body shone a great golden flashlight to illuminate our little patch of earth. It’s the same trick of perspective that the brain plays to make parallel railroad tracks look like they converge at a distance.
There certainly are other beautiful effects of light and shadow, scattering and perspective to be seen in the sky, but I think crepuscular rays are some of the most evocative. Perhaps it’s because they do seem to be flooding the earth with golden light, almost like a curtain opening up onto earth’s stage, as directed by something bigger than ourselves. Next time you see them, you’ll know that they are caused by natural circumstances, but you can always let those pretty rays take your gaze up into the sky. I assure you there will always be something interesting to see in “the heavens.”
Until next week, my friends, enjoy the view.
Wednesday, June 27, 2007
Summer Vacations
7/1/07 – 7/7/07
By C. Zaitz
‘Tis the season to get away. Whether it is vacation travel time, visiting relatives time, or maybe just taking a vacation in your mind time, most folks like to change locations in the summer. I’m often asked about how the sky changes when you travel. The answer is: it depends on where you’re going! If you are traveling mostly due east or west, you don’t have to worry. You’ll see pretty much the same sky you will “here,” at pretty much the same time of the evening, give or take some minutes depending on how close you are to the edge of your time zone. For example, if you travel to Chicago from Detroit, you’ll notice a large difference in actual sunset time. Chicago is on the eastern edge of the Central zone, and we are on the western edge of the Eastern. We gain an hour by traveling to Chicago, so though physically the two cities aren’t that far apart, Detroit has sunset around 9pm EDT, and Chicago sees it at 8:15pm CDT.
If you’re traveling north or south of “here” (wherever you are), you’ll start to see some differences. From Michigan and pretty much anywhere in the US, the solar system objects make a path across the southern sky as they seem to travel east to west. The further south you go, the higher they will be in the sky. As you travel close to the equator, they will be above your head. As you go south of the equator, you’ll notice the parade of planets across the northern sky, but they’ll still be in the same order. Currently Venus is closest to the western horizon at sunset, followed by Saturn, with Jupiter bringing up the rear furthest toward the east. They will still seem to travel east to west, so the only difference is that you’ll be looking north, rather than south to see them.
The constellations do vary with latitude, but not that much within the US. If you travel north of here, you won’t add any new constellations to your repertoire; we see all the northern ones throughout the year already. If you go significantly south, perhaps beyond Miami, you will see sights never seen from our latitude. This is the realm of the hopelessly obscure constellations. If you thought Cancer (the crab) and Monoceros (the unicorn) were hard to find, try finding Antlia (the pump) or Norma (the carpenter’s square). I may be biased, but I think most of the groovy constellations are in the northern skies. That’s no excuse to stay home this summer, though!
I think the main difference you’ll find as you travel is the view of the sky in general. There aren’t too many places left that are unpolluted by street lights, but when you travel, chances are greater that you may find a few of them. I think that the mind actually sighs when it sees the vast number of stars of the Milky Way in a velvety black summer night sky. That’s when it begins to get rid of the hassles and worries of the long cold months and begins to finally get a change of perspective. And for me, that’s when the vacation really begins!
Until next week, my friends, enjoy the view.
By C. Zaitz
‘Tis the season to get away. Whether it is vacation travel time, visiting relatives time, or maybe just taking a vacation in your mind time, most folks like to change locations in the summer. I’m often asked about how the sky changes when you travel. The answer is: it depends on where you’re going! If you are traveling mostly due east or west, you don’t have to worry. You’ll see pretty much the same sky you will “here,” at pretty much the same time of the evening, give or take some minutes depending on how close you are to the edge of your time zone. For example, if you travel to Chicago from Detroit, you’ll notice a large difference in actual sunset time. Chicago is on the eastern edge of the Central zone, and we are on the western edge of the Eastern. We gain an hour by traveling to Chicago, so though physically the two cities aren’t that far apart, Detroit has sunset around 9pm EDT, and Chicago sees it at 8:15pm CDT.
If you’re traveling north or south of “here” (wherever you are), you’ll start to see some differences. From Michigan and pretty much anywhere in the US, the solar system objects make a path across the southern sky as they seem to travel east to west. The further south you go, the higher they will be in the sky. As you travel close to the equator, they will be above your head. As you go south of the equator, you’ll notice the parade of planets across the northern sky, but they’ll still be in the same order. Currently Venus is closest to the western horizon at sunset, followed by Saturn, with Jupiter bringing up the rear furthest toward the east. They will still seem to travel east to west, so the only difference is that you’ll be looking north, rather than south to see them.
The constellations do vary with latitude, but not that much within the US. If you travel north of here, you won’t add any new constellations to your repertoire; we see all the northern ones throughout the year already. If you go significantly south, perhaps beyond Miami, you will see sights never seen from our latitude. This is the realm of the hopelessly obscure constellations. If you thought Cancer (the crab) and Monoceros (the unicorn) were hard to find, try finding Antlia (the pump) or Norma (the carpenter’s square). I may be biased, but I think most of the groovy constellations are in the northern skies. That’s no excuse to stay home this summer, though!
I think the main difference you’ll find as you travel is the view of the sky in general. There aren’t too many places left that are unpolluted by street lights, but when you travel, chances are greater that you may find a few of them. I think that the mind actually sighs when it sees the vast number of stars of the Milky Way in a velvety black summer night sky. That’s when it begins to get rid of the hassles and worries of the long cold months and begins to finally get a change of perspective. And for me, that’s when the vacation really begins!
Until next week, my friends, enjoy the view.
Wednesday, June 20, 2007
Not Just a Pretty Sky
6/24/07 – 6/30/07
C. Zaitz
I am in the habit of telling people to look in the sky to see various things like planets or the moon. Then I will invariably say “it’s so pretty, just look east, blah blah etc.” Recently I was called on to clarify my statement. “So just what do you mean by pretty? What colors? What should we expect to see?” “Um, well, uh, it’s just pretty,” was all I could say.
I know people want to know what to expect, but describing beauty in the sky is tough, since it’s in the eye of the beholder. I’m always tilting upward to check out the sky, even during the day. I find beauty in the cloud formations, in the gradation of blue to white in a daytime sky, in the windblown condensation trails left behind by high flying jets. But such visceral experiences are hard to put it into words. Words are for the explanation of what a contrail is, but when I’m just enjoying it, I fall silent. I think that’s a pretty common human experience.
Recently the crescent moon, Venus, Saturn and a bright star Regulus were in alignment in the western sky. My parents were visiting so I showed them the line of objects and extended it over to Jupiter, also along the ecliptic, or plane of the solar system as seen from earth. But rather than going into the whole explanation of what we were seeing, I just pointed to them and named them. I know that some people would rather just enjoy the view rather than knowing what they were looking at and why.
On the other hand, sometimes knowing is good. In the past, and even still today, there are folks who would rather make a leap of the imagination and say that the alignment meant something, such as an omen or a foreshadowing. It is unusual it is to have such an alignment of bright objects in the sky. Unusual because it doesn’t happen every night, or even every month, but it is to be expected from time to time, since the planets do all travel the same highway, the ecliptic. For me there’s no need to assign a special significance to it other than “it’s really pretty when it happens.”
The other night I went out on a hot, humid night to gaze at the setting moon and Venus, and they were both tinted orangey red. Immediately I thought “how beautiful, a blood red crescent moon.” It occurred to me that some people in the world might think that something was wrong, that maybe the moon had exploded or was on fire. The truth was not that exciting. It was reddish because there was a lot of water vapor in the air. That’s why it felt so humid. It is the same light extinction that happens when the sun is low along the horizon making gorgeous sunsets on humid days. Knowing it allowed me to appreciate the science and the art at the same time.
There’s definitely a time and place for just looking, but we shouldn’t forget the depth behind the beauty; there are reasons for why things are the way they are. For me, knowing the reasons adds another dimension to the view, but doesn’t make it any less “pretty.” And it helps scare away the ghosts of superstition.
Until next week, my friends, enjoy the view.
C. Zaitz
I am in the habit of telling people to look in the sky to see various things like planets or the moon. Then I will invariably say “it’s so pretty, just look east, blah blah etc.” Recently I was called on to clarify my statement. “So just what do you mean by pretty? What colors? What should we expect to see?” “Um, well, uh, it’s just pretty,” was all I could say.
I know people want to know what to expect, but describing beauty in the sky is tough, since it’s in the eye of the beholder. I’m always tilting upward to check out the sky, even during the day. I find beauty in the cloud formations, in the gradation of blue to white in a daytime sky, in the windblown condensation trails left behind by high flying jets. But such visceral experiences are hard to put it into words. Words are for the explanation of what a contrail is, but when I’m just enjoying it, I fall silent. I think that’s a pretty common human experience.
Recently the crescent moon, Venus, Saturn and a bright star Regulus were in alignment in the western sky. My parents were visiting so I showed them the line of objects and extended it over to Jupiter, also along the ecliptic, or plane of the solar system as seen from earth. But rather than going into the whole explanation of what we were seeing, I just pointed to them and named them. I know that some people would rather just enjoy the view rather than knowing what they were looking at and why.
On the other hand, sometimes knowing is good. In the past, and even still today, there are folks who would rather make a leap of the imagination and say that the alignment meant something, such as an omen or a foreshadowing. It is unusual it is to have such an alignment of bright objects in the sky. Unusual because it doesn’t happen every night, or even every month, but it is to be expected from time to time, since the planets do all travel the same highway, the ecliptic. For me there’s no need to assign a special significance to it other than “it’s really pretty when it happens.”
The other night I went out on a hot, humid night to gaze at the setting moon and Venus, and they were both tinted orangey red. Immediately I thought “how beautiful, a blood red crescent moon.” It occurred to me that some people in the world might think that something was wrong, that maybe the moon had exploded or was on fire. The truth was not that exciting. It was reddish because there was a lot of water vapor in the air. That’s why it felt so humid. It is the same light extinction that happens when the sun is low along the horizon making gorgeous sunsets on humid days. Knowing it allowed me to appreciate the science and the art at the same time.
There’s definitely a time and place for just looking, but we shouldn’t forget the depth behind the beauty; there are reasons for why things are the way they are. For me, knowing the reasons adds another dimension to the view, but doesn’t make it any less “pretty.” And it helps scare away the ghosts of superstition.
Until next week, my friends, enjoy the view.
Thursday, June 14, 2007
Close Encounters
6/17/07 – 6/23/07
by C. Zaitz
Every summer, an email floats around the internet about Mars. The email tells us that no one alive will ever see this again. It’s a once in a lifetime event. Don’t miss it. Then the email says that Mars is as close as it will be for 5,000 or maybe even 60,000 years. However, the same email comes back every year, and most of it is hype. Technically, earth and Mars were closest to each other in August of 2003, but every time earth passes Mars, we have a close encounter. Human eyes can’t discern the difference between when Mars is 35 million miles from us or 40 million miles. It would be like looking at a baseball 400 miles away. You can’t really tell if it’s 50 miles closer with the unaided eye because it’s so small compared to its distance.
Currently, Mars isn’t even a player in the night sky. But there are three planets that are. Jupiter, for one. If you’re looking for close encounters, it happens that we are closer to Jupiter this month than at other times in the year, and it is definitely showing off brightly all night long. “Closest” simply means that we are on the same side of the sun as Jupiter. Imagine a Nascar track with earth on an inside lane and Jupiter further toward the outside edge. Because we are going faster and have less space to travel, we pass Jupiter. As we pass, we are closer than we are at other times. It’s happening now, and it’s a great time to use your binoculars to see Jupiter and its largest moons. If you want a fun project with kids, you can even watch it from night to night and see how the moons move around Jupiter, just like the famous astronomer Galileo did. Use a sketch pad and draw the configuration. Kids (and adults) can actually see something changing in the sky, and you never know what will spark a life-long interest in science. Galileo’s sketches changed the way people thought, and forever put to rest the idea that the earth was the center of everything.
Saturn is also up in the evening sky, but sets an hour or two after dark. Saturn is even more astounding when you see it through a telescope. Often we are jaded by seeing full color giant images of planets and space objects from the Hubble Space Telescope. But there is something special about seeing Saturn through a small telescope. You can’t see color, and it looks tiny, but you can see the rings and even a moon. It’s nearly twice as far away as Jupiter, but it is so distinctive that you really know you’re looking at a planet, not just a bright light. I highly recommend it this summer, especially with kids.
The third bright planet up in the early evening is Venus. She’s been especially showy lately, high in the west during evening twilight, and shining more brightly than airplane headlights. Her reflective clouds send a lot of sunlight our way, and because you can see her at sunset, she’s the planet you’ll notice most. At the end of June, she’ll be close to Saturn, and this will be the prettiest close encounter of all. Just look to the west as it gets dark enough to see them, around 9:45-10 pm.
Until next week, my friends, enjoy the view.
by C. Zaitz
Every summer, an email floats around the internet about Mars. The email tells us that no one alive will ever see this again. It’s a once in a lifetime event. Don’t miss it. Then the email says that Mars is as close as it will be for 5,000 or maybe even 60,000 years. However, the same email comes back every year, and most of it is hype. Technically, earth and Mars were closest to each other in August of 2003, but every time earth passes Mars, we have a close encounter. Human eyes can’t discern the difference between when Mars is 35 million miles from us or 40 million miles. It would be like looking at a baseball 400 miles away. You can’t really tell if it’s 50 miles closer with the unaided eye because it’s so small compared to its distance.
Currently, Mars isn’t even a player in the night sky. But there are three planets that are. Jupiter, for one. If you’re looking for close encounters, it happens that we are closer to Jupiter this month than at other times in the year, and it is definitely showing off brightly all night long. “Closest” simply means that we are on the same side of the sun as Jupiter. Imagine a Nascar track with earth on an inside lane and Jupiter further toward the outside edge. Because we are going faster and have less space to travel, we pass Jupiter. As we pass, we are closer than we are at other times. It’s happening now, and it’s a great time to use your binoculars to see Jupiter and its largest moons. If you want a fun project with kids, you can even watch it from night to night and see how the moons move around Jupiter, just like the famous astronomer Galileo did. Use a sketch pad and draw the configuration. Kids (and adults) can actually see something changing in the sky, and you never know what will spark a life-long interest in science. Galileo’s sketches changed the way people thought, and forever put to rest the idea that the earth was the center of everything.
Saturn is also up in the evening sky, but sets an hour or two after dark. Saturn is even more astounding when you see it through a telescope. Often we are jaded by seeing full color giant images of planets and space objects from the Hubble Space Telescope. But there is something special about seeing Saturn through a small telescope. You can’t see color, and it looks tiny, but you can see the rings and even a moon. It’s nearly twice as far away as Jupiter, but it is so distinctive that you really know you’re looking at a planet, not just a bright light. I highly recommend it this summer, especially with kids.
The third bright planet up in the early evening is Venus. She’s been especially showy lately, high in the west during evening twilight, and shining more brightly than airplane headlights. Her reflective clouds send a lot of sunlight our way, and because you can see her at sunset, she’s the planet you’ll notice most. At the end of June, she’ll be close to Saturn, and this will be the prettiest close encounter of all. Just look to the west as it gets dark enough to see them, around 9:45-10 pm.
Until next week, my friends, enjoy the view.
Wednesday, June 06, 2007
Crowning Glory
6/10/07 - 6/16/07
I happen to have a rather large collection of jewelry. Big piles of it. Drawers of it. Most of it is costume jewelry, just shiny cut glass, but that’s the stuff I love. I’ve been collecting it since kindergarten. I remember playing with a small wooden dresser at school and opening a drawer that contained a shiny necklace. I’m pretty sure I didn’t know what rhinestones were and thought I had found the crown jewels, so I promptly plopped the thing on my head, a gesture that pronounced me princess of the kindergarten class. Silly, but my fascination with rhinestones never wore off.
It was about that time that I fell in love with the sky. Was it the sparkly nature of it that drew me? Perhaps, but what I didn’t know then but to my great pleasure learned later, is that there is a sparkly crown in the sky. It’s called Corona Borealis and it crowns the sky in late spring and summer. Corona is Latin for crown, and borealis refers to the fact it’s in the northern sky, not to be confused with Corona Australis, the much less impressive Southern Crown. The northern circlet is made of seven stars, none of which are especially bright. The brightest is called Gemma, aptly named as the shiniest gem star. It’s not directly in the center, but fairly close to it.
Corona Borealis is found high in the sky, close between Hercules and Bootes. Once you find it, you may get a little thrill of seeing princess Ariadne’s crown in the sky. She was the daughter of King Minos of Crete and Pasiphae. Thanks to her mother, Ariadne was also half-sister to the Minotaur, the half bull, half human creature that lived in the labyrinth of Crete. The labyrinth was a riotous collection of maze-like hallways, a perfect home for hiding the human-flesh eating Minotaur. Pasiphae had known he was a terrible beast even as a baby, but hadn’t the heart to kill him, so he grew to be a terrible menace. To pacify the monster, each year King Minos chose seven male and seven female Athenian youths to sacrifice to the creature. One year the son of the king of Athens, Theseus, decided to put an end to this annual gruesome slaughter. He joined the group of sacrificial victims and went to meet the Minotaur.
Meanwhile, Ariadne had caught a glimpse of the handsome Theseus and instantly fell in love with him. She decided to help him by giving him a sword and a ball of thread. The sword’s purpose was obvious, but the thread was what saved Theseus from being hopelessly lost in the labyrinth. Theseus did slay the Minotaur, and was able to rescue himself and other victims by following the thread back through the labyrinth to safety. Theseus rewarded Ariadne briefly for her help by taking her to the island of Naxos, but there he abandoned her. She managed to catch the eye of Dionysus, the god of wine, who felt sorry for her and married her. He is the one who gave her the crown now seen in the evening sky.
Now we can all enjoy having a crown above our heads. Sure, it’s made of stars, not diamonds, but as with my pretty rhinestone necklace, you can make of it what you will. And now you can think of the story of Ariadne and Theseus and join the kingdom of people who have done so since early times.
Until next week, my friends, enjoy the view.
I happen to have a rather large collection of jewelry. Big piles of it. Drawers of it. Most of it is costume jewelry, just shiny cut glass, but that’s the stuff I love. I’ve been collecting it since kindergarten. I remember playing with a small wooden dresser at school and opening a drawer that contained a shiny necklace. I’m pretty sure I didn’t know what rhinestones were and thought I had found the crown jewels, so I promptly plopped the thing on my head, a gesture that pronounced me princess of the kindergarten class. Silly, but my fascination with rhinestones never wore off.
It was about that time that I fell in love with the sky. Was it the sparkly nature of it that drew me? Perhaps, but what I didn’t know then but to my great pleasure learned later, is that there is a sparkly crown in the sky. It’s called Corona Borealis and it crowns the sky in late spring and summer. Corona is Latin for crown, and borealis refers to the fact it’s in the northern sky, not to be confused with Corona Australis, the much less impressive Southern Crown. The northern circlet is made of seven stars, none of which are especially bright. The brightest is called Gemma, aptly named as the shiniest gem star. It’s not directly in the center, but fairly close to it.
Corona Borealis is found high in the sky, close between Hercules and Bootes. Once you find it, you may get a little thrill of seeing princess Ariadne’s crown in the sky. She was the daughter of King Minos of Crete and Pasiphae. Thanks to her mother, Ariadne was also half-sister to the Minotaur, the half bull, half human creature that lived in the labyrinth of Crete. The labyrinth was a riotous collection of maze-like hallways, a perfect home for hiding the human-flesh eating Minotaur. Pasiphae had known he was a terrible beast even as a baby, but hadn’t the heart to kill him, so he grew to be a terrible menace. To pacify the monster, each year King Minos chose seven male and seven female Athenian youths to sacrifice to the creature. One year the son of the king of Athens, Theseus, decided to put an end to this annual gruesome slaughter. He joined the group of sacrificial victims and went to meet the Minotaur.
Meanwhile, Ariadne had caught a glimpse of the handsome Theseus and instantly fell in love with him. She decided to help him by giving him a sword and a ball of thread. The sword’s purpose was obvious, but the thread was what saved Theseus from being hopelessly lost in the labyrinth. Theseus did slay the Minotaur, and was able to rescue himself and other victims by following the thread back through the labyrinth to safety. Theseus rewarded Ariadne briefly for her help by taking her to the island of Naxos, but there he abandoned her. She managed to catch the eye of Dionysus, the god of wine, who felt sorry for her and married her. He is the one who gave her the crown now seen in the evening sky.
Now we can all enjoy having a crown above our heads. Sure, it’s made of stars, not diamonds, but as with my pretty rhinestone necklace, you can make of it what you will. And now you can think of the story of Ariadne and Theseus and join the kingdom of people who have done so since early times.
Until next week, my friends, enjoy the view.
Tuesday, May 29, 2007
Messier Sky
6/3/07 – 6/9/07
by C. Zaitz
It is my opinion that summertime is the very best time for evening sky watching, whether you are a casual looker, an interested observer or a hard-core “Messier object” junkie. I’ve been all three at various times, but summer is the time when we can spend more quality time outside at night, gazing upward, finding your “fix” in the stars. Beyond knowing the constellations, if you really want to get to know the universe, finding Messier objects is a good way to do it. (Messier doesn’t refer to the chaos of the sky, it’s the last name of French astronomer Charles Messi “ay.”)
Monsieur Messier was an observational astronomer at the end of the 18th century who was very interested in finding new comets. This was a popular past time for an astronomer seeking to be immortalized by getting a comet named after him. However, Messier was annoyed with the countless fuzzy clouds in space that were easily confused with fuzzy comets. Messier catalogued over 100 “nebulae,” which were thought to be some sort of cloud within the galaxy. He hoped to save himself and other comet hunters the confusion of wondering if the faint fuzzy was indeed a fame-inducing object, or merely another “cloud.”
The existence of other galaxies beyond the Milky Way was not known until William Herschel and others continued cataloguing the fuzzy objects. The Herschel General Catalogue of Nebulae, listing over 5,000 objects, gave way to the New General Catalogue (NGC) in 1888, which contained nearly 8,000. Soon their true nature became clear- these clouds were not of the Milky Way at all, but each a separate “island universe” like our own. And Messier’s catalogue of galaxies, nebulae and supernovae remnants gave him more fame than any comet would have. Amateur astronomers world-over know of Messier and his wonderful catalogue of deep space objects. The NGC does not immortalize its author, but contains Messier objects as well as many more interesting destinations for the observer with time and telescope on hand.
The summer skies hold many Messier objects, known by their “M” number. Many of them have very pretty nicknames. For example, M57 is the Ring Nebula, M101 is the Pinwheel Galaxy and M104 is the Sombrero Galaxy. Other nick names are not so lovely; such as the Blackeye galaxy (M64), the Crab Nebula (M1), and the Dumbbell Nebula (M27). Cute name or not, one of the most beautiful sights to see in the late spring and summer is M13, the lovely globular cluster of stars in Hercules. A globular cluster is a tightly packed group of older stars. In M13 there are estimated to be over a million stars in a sphere of space about 100 light years across. You can see the Hercules cluster with binoculars, but it truly is best seen through a telescope.
M57, the Ring Nebula in Lyra is also a pretty sight in a telescope. It is the first planetary nebula ever discovered. It looks like an ethereal smoke ring in the black sky, but it is the outer shells of a dying star, suffering the same fate as will our sun, in some 5 billion years.
There are many more such objects within view of a typical amateur telescope, and summer amateur group star parties are the best way to see these sights, and to get to know those folks who can help you discover the universe of Messier deep space objects.
Until next week, my friends, enjoy the view.
by C. Zaitz
It is my opinion that summertime is the very best time for evening sky watching, whether you are a casual looker, an interested observer or a hard-core “Messier object” junkie. I’ve been all three at various times, but summer is the time when we can spend more quality time outside at night, gazing upward, finding your “fix” in the stars. Beyond knowing the constellations, if you really want to get to know the universe, finding Messier objects is a good way to do it. (Messier doesn’t refer to the chaos of the sky, it’s the last name of French astronomer Charles Messi “ay.”)
Monsieur Messier was an observational astronomer at the end of the 18th century who was very interested in finding new comets. This was a popular past time for an astronomer seeking to be immortalized by getting a comet named after him. However, Messier was annoyed with the countless fuzzy clouds in space that were easily confused with fuzzy comets. Messier catalogued over 100 “nebulae,” which were thought to be some sort of cloud within the galaxy. He hoped to save himself and other comet hunters the confusion of wondering if the faint fuzzy was indeed a fame-inducing object, or merely another “cloud.”
The existence of other galaxies beyond the Milky Way was not known until William Herschel and others continued cataloguing the fuzzy objects. The Herschel General Catalogue of Nebulae, listing over 5,000 objects, gave way to the New General Catalogue (NGC) in 1888, which contained nearly 8,000. Soon their true nature became clear- these clouds were not of the Milky Way at all, but each a separate “island universe” like our own. And Messier’s catalogue of galaxies, nebulae and supernovae remnants gave him more fame than any comet would have. Amateur astronomers world-over know of Messier and his wonderful catalogue of deep space objects. The NGC does not immortalize its author, but contains Messier objects as well as many more interesting destinations for the observer with time and telescope on hand.
The summer skies hold many Messier objects, known by their “M” number. Many of them have very pretty nicknames. For example, M57 is the Ring Nebula, M101 is the Pinwheel Galaxy and M104 is the Sombrero Galaxy. Other nick names are not so lovely; such as the Blackeye galaxy (M64), the Crab Nebula (M1), and the Dumbbell Nebula (M27). Cute name or not, one of the most beautiful sights to see in the late spring and summer is M13, the lovely globular cluster of stars in Hercules. A globular cluster is a tightly packed group of older stars. In M13 there are estimated to be over a million stars in a sphere of space about 100 light years across. You can see the Hercules cluster with binoculars, but it truly is best seen through a telescope.
M57, the Ring Nebula in Lyra is also a pretty sight in a telescope. It is the first planetary nebula ever discovered. It looks like an ethereal smoke ring in the black sky, but it is the outer shells of a dying star, suffering the same fate as will our sun, in some 5 billion years.
There are many more such objects within view of a typical amateur telescope, and summer amateur group star parties are the best way to see these sights, and to get to know those folks who can help you discover the universe of Messier deep space objects.
Until next week, my friends, enjoy the view.
Wednesday, May 23, 2007
Magnetism
5/27/07 – 6/2/07
by C. Zaitz
The earth is cooling. It had to. When it formed some 4.6 billion years ago, it was way too hot for any life to form. In fact, it’s taken a lot of time to cool enough for rhinos and beavers and gazelles to be able to roam freely without burning their hooves and paws and giant feet. Much of earth’s history has been spent cooling and changing into the planet we know and love. Unfortunately, earth doesn’t know and love us. It keeps changing, whether or not the life forms occupying its surface can survive it or not. It cares not whether its atmosphere grows thick or thin, whether its waters are pure, or if its movements will disrupt the parasites on its edge.
We know that huge volcanic eruptions and earthquakes can cause widespread destruction. They are caused by the movement of the plates of crust and mantle. Deeper within the earth lies the mechanism for creating an invisible shield, a barrier against the killing radiation from the sun. The earth has a fairly strong magnetic field, created and maintained by the movements of its liquid metallic outer core. The field extends out into space like a giant protective web. We have learned about the nature of our magnetic field from looking at the bottom of the ocean at the mid-Atlantic ridge. As magma flows out from the crack between two separating tectonic plates, little bits of magnetic material align in the direction of earth’s magnetic field. It hardens and the magnetic record is solidified. We can read the ocean floor like a book, and it’s telling us that over time the magnetic field of the earth changes. Sometimes it is aligned as it is now, but other times it’s completely switched. The north magnetic pole is sometimes in the southern hemisphere! What’s nerve-wracking is that while it’s switching, it can weaken and be non-existent for awhile. Our mid-Atlantic story book is telling us that it may be time for another switch. Or even more harrowing, as the earth cools and the outer core solidifies, the magnetic field may disappear forever.
Though we don’t often notice the effects of the magnetic field in our daily lives, it does provide an invisible barrier from the harsher radiation from the sun. We’re all familiar with the northern lights, which are caused by high energy solar radiation interacting with our atmosphere, spiraling in along the magnetic field lines near the poles. But what we’re not aware of is the daily bombardment of high energy particles from the sun that are deflected away from us. Without our magnetic field, we would be exposed to much more radiation than we’re used to, and it could be very harmful to all life forms on earth.
Between earth’s mantle and the cold, stark emptiness of outer space, lie the layers of geology that hold our history. Creatures have come and gone in the 3 billion year history of life on earth. It started with single celled organisms and has proliferated in the multifarious beings of today. But the creatures that were around 100 million years ago are not necessarily the ones we see now. Life has changed, often in big sweeping changes caused by the earth itself. Our magnetic field may be an important part of the plot of how life on earth changes, and we may be in store for the next chapter in the book. I hope it has a happy ending!
Until next week, my friends, enjoy the view.
by C. Zaitz
The earth is cooling. It had to. When it formed some 4.6 billion years ago, it was way too hot for any life to form. In fact, it’s taken a lot of time to cool enough for rhinos and beavers and gazelles to be able to roam freely without burning their hooves and paws and giant feet. Much of earth’s history has been spent cooling and changing into the planet we know and love. Unfortunately, earth doesn’t know and love us. It keeps changing, whether or not the life forms occupying its surface can survive it or not. It cares not whether its atmosphere grows thick or thin, whether its waters are pure, or if its movements will disrupt the parasites on its edge.
We know that huge volcanic eruptions and earthquakes can cause widespread destruction. They are caused by the movement of the plates of crust and mantle. Deeper within the earth lies the mechanism for creating an invisible shield, a barrier against the killing radiation from the sun. The earth has a fairly strong magnetic field, created and maintained by the movements of its liquid metallic outer core. The field extends out into space like a giant protective web. We have learned about the nature of our magnetic field from looking at the bottom of the ocean at the mid-Atlantic ridge. As magma flows out from the crack between two separating tectonic plates, little bits of magnetic material align in the direction of earth’s magnetic field. It hardens and the magnetic record is solidified. We can read the ocean floor like a book, and it’s telling us that over time the magnetic field of the earth changes. Sometimes it is aligned as it is now, but other times it’s completely switched. The north magnetic pole is sometimes in the southern hemisphere! What’s nerve-wracking is that while it’s switching, it can weaken and be non-existent for awhile. Our mid-Atlantic story book is telling us that it may be time for another switch. Or even more harrowing, as the earth cools and the outer core solidifies, the magnetic field may disappear forever.
Though we don’t often notice the effects of the magnetic field in our daily lives, it does provide an invisible barrier from the harsher radiation from the sun. We’re all familiar with the northern lights, which are caused by high energy solar radiation interacting with our atmosphere, spiraling in along the magnetic field lines near the poles. But what we’re not aware of is the daily bombardment of high energy particles from the sun that are deflected away from us. Without our magnetic field, we would be exposed to much more radiation than we’re used to, and it could be very harmful to all life forms on earth.
Between earth’s mantle and the cold, stark emptiness of outer space, lie the layers of geology that hold our history. Creatures have come and gone in the 3 billion year history of life on earth. It started with single celled organisms and has proliferated in the multifarious beings of today. But the creatures that were around 100 million years ago are not necessarily the ones we see now. Life has changed, often in big sweeping changes caused by the earth itself. Our magnetic field may be an important part of the plot of how life on earth changes, and we may be in store for the next chapter in the book. I hope it has a happy ending!
Until next week, my friends, enjoy the view.
Tuesday, May 15, 2007
The Short and the Long
5/21/07 – 5/27/07
by C. Zaitz
I just had one of those milestone birthdays- you know, the ones that are supposed to be more special than the rest because the number is getting so high that you have to celebrate just being alive. It made me think of the age of things. Biologically, things happen on a pretty short time scale. 70-80 years is not that long when you take into consideration how long rocks live. In astronomy we talk about ages of stars, in geology we talk about the ages of rocks and planets. In human lifescales, those numbers are incomprehensible. We have no feeling for how long it takes a rock to form, much less a star. It seems like eternity to wait for your tomatoes to ripen or for your hair to grow out after a bad cut!
Though humans have a relatively short lifespan, we are still around long enough to watch things grow and develop, die and transform. Plants and animals live in our time scale, though we marvel at the 2,000 year old sequoias and ancient cedars. But things we think of as everlasting, like rocks or stars, are not eternal. All rocks move through a cycle, from being sand sediments on the surface, to being metamorphised as the pressure of layers upon layers of rock change its character, to suffering the igneous fate of melted rocks, turning into magma and reforming on the surface as lava basalt, only to be worn away again as sand and sediment. Eons pass and the dirt just keeps changing form, nothing destroyed or created, but morphing from one form to another.
The same thing happens with stars. Our sun was once diffuse gas and dust, our own planet not more than a breath of cosmic debris, sprinkled with rare elements fused in the death throes of an ancestor star. Gravity and pressure brought everything around, and our solar system will go for at least as long as it already has, some 4.5 billion years. Then it will die, only to form something new in the next “billenia.” Will it be something completely different? A double star or part of a new open cluster of stars? Or maybe a familiar life-harboring solar system?
We happen to be living in a very particular time when we as a species can begin to understand all the cycles of life and death around us. How unique and incredible for us. It’s not surprising we’re so curious about the universe, since we see our own selves reflected in the life cycles, in the growing and dying of everything around us. I think we study these cycles to try to understand what happens when we, too, die. Will we be born again in some “next cycle?”
From an old southern banjo tune:
Little birdie, little birdie,
come sing to me your song.
I've a short while to be here,
and a long time to be gone.
Little birdie, little birdie,
What makes you fly so high?
It’s because I am a true little bird
and I do not fare to die.
I guess I like to think that nothing really goes away. We all get older and will all die, but even black holes give up their dead eventually. Nothing seems to be destroyed, and it all comes back around again, sometimes in the near future, like perennial flowers, and sometimes in the long run, like planets with life.
Until next week, my friends, enjoy the view.
by C. Zaitz
I just had one of those milestone birthdays- you know, the ones that are supposed to be more special than the rest because the number is getting so high that you have to celebrate just being alive. It made me think of the age of things. Biologically, things happen on a pretty short time scale. 70-80 years is not that long when you take into consideration how long rocks live. In astronomy we talk about ages of stars, in geology we talk about the ages of rocks and planets. In human lifescales, those numbers are incomprehensible. We have no feeling for how long it takes a rock to form, much less a star. It seems like eternity to wait for your tomatoes to ripen or for your hair to grow out after a bad cut!
Though humans have a relatively short lifespan, we are still around long enough to watch things grow and develop, die and transform. Plants and animals live in our time scale, though we marvel at the 2,000 year old sequoias and ancient cedars. But things we think of as everlasting, like rocks or stars, are not eternal. All rocks move through a cycle, from being sand sediments on the surface, to being metamorphised as the pressure of layers upon layers of rock change its character, to suffering the igneous fate of melted rocks, turning into magma and reforming on the surface as lava basalt, only to be worn away again as sand and sediment. Eons pass and the dirt just keeps changing form, nothing destroyed or created, but morphing from one form to another.
The same thing happens with stars. Our sun was once diffuse gas and dust, our own planet not more than a breath of cosmic debris, sprinkled with rare elements fused in the death throes of an ancestor star. Gravity and pressure brought everything around, and our solar system will go for at least as long as it already has, some 4.5 billion years. Then it will die, only to form something new in the next “billenia.” Will it be something completely different? A double star or part of a new open cluster of stars? Or maybe a familiar life-harboring solar system?
We happen to be living in a very particular time when we as a species can begin to understand all the cycles of life and death around us. How unique and incredible for us. It’s not surprising we’re so curious about the universe, since we see our own selves reflected in the life cycles, in the growing and dying of everything around us. I think we study these cycles to try to understand what happens when we, too, die. Will we be born again in some “next cycle?”
From an old southern banjo tune:
Little birdie, little birdie,
come sing to me your song.
I've a short while to be here,
and a long time to be gone.
Little birdie, little birdie,
What makes you fly so high?
It’s because I am a true little bird
and I do not fare to die.
I guess I like to think that nothing really goes away. We all get older and will all die, but even black holes give up their dead eventually. Nothing seems to be destroyed, and it all comes back around again, sometimes in the near future, like perennial flowers, and sometimes in the long run, like planets with life.
Until next week, my friends, enjoy the view.
Wednesday, May 09, 2007
A Weighty Subject
5/13/07 – 5/20/07
by C. Zaitz
My husband recently lost about 35 pounds due to having a very overactive thyroid gland. After an intense potion of radiation, it calmed down, so we started going back to the gym for workouts. He picked up a 35 pound weight and gave it to me to feel how much weight he’d lost. It seemed very heavy, but he carried it around for years. I started to think about weight and how we measure it, and how hard it is to lose it.
Weight is a combination of how much gravity pulls down on us, and how much “us” there is. Often in everyday life we confuse “mass” and “weight.” Mass is an intrinsic property of something, measured in pounds or kilograms. It’s how much “stuff” there is. If our mass was 150 kg on earth, it would still be 150 kg on the moon. But we wouldn’t weigh as much there, because the moon has much less gravity than earth. To get our weight, we would have to multiply our mass by how much gravity our “ground” has. Since we all live on earth and have nearly the same amount of gravity tugging on us, we forget the fact that weight and mass are different things.
Interestingly, if there were no floor or surface to stand on, you wouldn’t feel weight at all. If the floor wasn’t “pushing” back on you as hard as gravity is pulling you toward the center of the earth, you would just fall in, feeling no weight at all. This is “free fall” or “weightlessness.” It’s hard to do on earth, but the astronauts in orbit are very familiar with it. The astronauts and the space station might not have any “weight” in orbit, but they certainly have mass, which takes energy to move. That’s why it takes a lot of fuel to move stuff around even in “weightlessness.”
The fun comes when we figure out how much we’d weigh on other planets. Which would you choose, big planet or small? A 150 pound person would weigh 57 pounds on Mars. On the moon, you’d weigh a mere 25 pounds. But things get weird when you go to one of the giant, gassy planets. You’d think a mammoth planet like Saturn, a planet that could engulf earth 760 times, would have an enormous amount gravity. It does, but the farther you get from the center, the force of gravity lessens exponentially. Saturn has about 95 times more mass than earth, but its radius is 9.4 times that of earth. The math works out that on the “surface” or visible gassy outer atmosphere of Saturn, you would weigh approximately what you do on earth. The same is true of Neptune and Uranus. Jupiter is the most massive planet, 318 times more than earth, but its radius is over 11 times earth’s. Its surface gravity turns out to be about 2.5 times that of earth’s. Our 150 pound person would only weigh 375 pounds on Jupiter. Not bad for the biggest planet of them all. On Saturn, this same person would weigh a svelte 137 pounds. So you can actually “lose” weight by going to Saturn. Not to mention the weight you’d lose by eating freeze-dried peas for the three years it would take to get there.
If you’d like to check your own weight on the planets, you can go to: http://www.exploratorium.edu/ronh/weight/index.html to plan your weight loss/gain itinerary.
Until next week, my friends, enjoy the view.
by C. Zaitz
My husband recently lost about 35 pounds due to having a very overactive thyroid gland. After an intense potion of radiation, it calmed down, so we started going back to the gym for workouts. He picked up a 35 pound weight and gave it to me to feel how much weight he’d lost. It seemed very heavy, but he carried it around for years. I started to think about weight and how we measure it, and how hard it is to lose it.
Weight is a combination of how much gravity pulls down on us, and how much “us” there is. Often in everyday life we confuse “mass” and “weight.” Mass is an intrinsic property of something, measured in pounds or kilograms. It’s how much “stuff” there is. If our mass was 150 kg on earth, it would still be 150 kg on the moon. But we wouldn’t weigh as much there, because the moon has much less gravity than earth. To get our weight, we would have to multiply our mass by how much gravity our “ground” has. Since we all live on earth and have nearly the same amount of gravity tugging on us, we forget the fact that weight and mass are different things.
Interestingly, if there were no floor or surface to stand on, you wouldn’t feel weight at all. If the floor wasn’t “pushing” back on you as hard as gravity is pulling you toward the center of the earth, you would just fall in, feeling no weight at all. This is “free fall” or “weightlessness.” It’s hard to do on earth, but the astronauts in orbit are very familiar with it. The astronauts and the space station might not have any “weight” in orbit, but they certainly have mass, which takes energy to move. That’s why it takes a lot of fuel to move stuff around even in “weightlessness.”
The fun comes when we figure out how much we’d weigh on other planets. Which would you choose, big planet or small? A 150 pound person would weigh 57 pounds on Mars. On the moon, you’d weigh a mere 25 pounds. But things get weird when you go to one of the giant, gassy planets. You’d think a mammoth planet like Saturn, a planet that could engulf earth 760 times, would have an enormous amount gravity. It does, but the farther you get from the center, the force of gravity lessens exponentially. Saturn has about 95 times more mass than earth, but its radius is 9.4 times that of earth. The math works out that on the “surface” or visible gassy outer atmosphere of Saturn, you would weigh approximately what you do on earth. The same is true of Neptune and Uranus. Jupiter is the most massive planet, 318 times more than earth, but its radius is over 11 times earth’s. Its surface gravity turns out to be about 2.5 times that of earth’s. Our 150 pound person would only weigh 375 pounds on Jupiter. Not bad for the biggest planet of them all. On Saturn, this same person would weigh a svelte 137 pounds. So you can actually “lose” weight by going to Saturn. Not to mention the weight you’d lose by eating freeze-dried peas for the three years it would take to get there.
If you’d like to check your own weight on the planets, you can go to: http://www.exploratorium.edu/ronh/weight/index.html to plan your weight loss/gain itinerary.
Until next week, my friends, enjoy the view.
Wednesday, May 02, 2007
Saturn in Leo
5/6/07 – 5/12/07
by C. Zaitz
Sometimes I take comfort in the thought that, as crazy as life gets here on earth, the planets are making their planetary journeys ‘round the sun in their own time. Each planet has its own pace, and the slowest, calmest naked-eye planet is Saturn. Right now Saturn is passing in front of the constellation Leo. Some folks say that this fact can be life altering.
For fun I looked up what astrologers have to say about the planet Saturn being “in” Leo. Because Saturn orbits so slowly, it spends more than two years in any one of the zodiac constellations. Saturn was the god of change, of destroying the old to make way for the new, so astrologers say. In his modern personification, he’s a teacher, and his tests are often difficult and life changing.
Astrologically, people born when the sun was “in” Leo tend to be leaders, and very involved with ego. So to have such a “destructive” planet in Leo seems to spell disaster for the top cats. But astrologers also say that if you are willing, Saturn’s life-changing presence can open up new doors and clean your inner house. That’s a lot of deep advice from the distant gas planet and the even more distant, boiling hot gas stars that make up the constellation of Leo. Recently I showed Leo to some 4th graders. They said that Leo looks like a smiley face or a pony or a balloon. This is not a very distinguished description of Leo, but nevertheless, kind of true. In general, constellations like Hercules or Sagittarius look nothing like a giant hero or a centaur. So to assign such lofty characteristics to a group of stars scattered through space is amusing to me. Of course, it’s crafty humans that come up with the characteristics, the shapes and the connections. And it’s searching humans that read their horoscopes and make connections with their own lives. It’s kind of interesting that not only do planets reflect sunlight back to us, but they reflect our own hopes and dreams, problems and possible solutions, back to us from afar.
As far as Saturn being “in” a constellation, right now is about 8 times the distance from the earth to the sun. It takes light about and hour and half to reach us from Saturn. Stars are much farther away. The brightest star in Leo, Regulus, is nearly 80 light years away from us. The planet actually moves “in front of” the stars of the constellation as it orbits, but it sounds more mysterious and inviting to say Saturn is “in” Leo, especially if you call that part of the sky a “house.”
If you want to see Saturn in Leo, look toward the south after sunset, about halfway up the sky, and look for the “sickle” or the backwards question mark shape of stars. That is the front part of Leo, if we imagine the round sickle blade as his head and golden mane. Saturn will be just to the right or west of the sickle. This spring, Saturn’s rings are prettily displayed for anyone with a telescope. Whether or not Saturn brings life altering events for you, you can still let the beauty of the reflected light dazzle your eyes and your mind. And that can be life altering as well, especially if it moves you to use the credit card to buy a new telescope!
Until next week, my friends, enjoy the view.
by C. Zaitz
Sometimes I take comfort in the thought that, as crazy as life gets here on earth, the planets are making their planetary journeys ‘round the sun in their own time. Each planet has its own pace, and the slowest, calmest naked-eye planet is Saturn. Right now Saturn is passing in front of the constellation Leo. Some folks say that this fact can be life altering.
For fun I looked up what astrologers have to say about the planet Saturn being “in” Leo. Because Saturn orbits so slowly, it spends more than two years in any one of the zodiac constellations. Saturn was the god of change, of destroying the old to make way for the new, so astrologers say. In his modern personification, he’s a teacher, and his tests are often difficult and life changing.
Astrologically, people born when the sun was “in” Leo tend to be leaders, and very involved with ego. So to have such a “destructive” planet in Leo seems to spell disaster for the top cats. But astrologers also say that if you are willing, Saturn’s life-changing presence can open up new doors and clean your inner house. That’s a lot of deep advice from the distant gas planet and the even more distant, boiling hot gas stars that make up the constellation of Leo. Recently I showed Leo to some 4th graders. They said that Leo looks like a smiley face or a pony or a balloon. This is not a very distinguished description of Leo, but nevertheless, kind of true. In general, constellations like Hercules or Sagittarius look nothing like a giant hero or a centaur. So to assign such lofty characteristics to a group of stars scattered through space is amusing to me. Of course, it’s crafty humans that come up with the characteristics, the shapes and the connections. And it’s searching humans that read their horoscopes and make connections with their own lives. It’s kind of interesting that not only do planets reflect sunlight back to us, but they reflect our own hopes and dreams, problems and possible solutions, back to us from afar.
As far as Saturn being “in” a constellation, right now is about 8 times the distance from the earth to the sun. It takes light about and hour and half to reach us from Saturn. Stars are much farther away. The brightest star in Leo, Regulus, is nearly 80 light years away from us. The planet actually moves “in front of” the stars of the constellation as it orbits, but it sounds more mysterious and inviting to say Saturn is “in” Leo, especially if you call that part of the sky a “house.”
If you want to see Saturn in Leo, look toward the south after sunset, about halfway up the sky, and look for the “sickle” or the backwards question mark shape of stars. That is the front part of Leo, if we imagine the round sickle blade as his head and golden mane. Saturn will be just to the right or west of the sickle. This spring, Saturn’s rings are prettily displayed for anyone with a telescope. Whether or not Saturn brings life altering events for you, you can still let the beauty of the reflected light dazzle your eyes and your mind. And that can be life altering as well, especially if it moves you to use the credit card to buy a new telescope!
Until next week, my friends, enjoy the view.
Wednesday, April 25, 2007
Goldilocks Planets
4/29/07 – 5/5/07
by C. Zaitz
The news is that astronomers have found a new planet orbiting a distant star. Astronomers have been finding planets in distant solar systems for decades, but usually the planets they discover are huge, more like Jupiter on steroids than anything earth-like. With better telescopes and more research, we are beginning to see the smaller planets. One in particular is being heralded as a “Goldilocks” planet, not too big, not too small, nor too cold, nor too hot. A “just right” planet that could possibly harbor liquid water, pretty sunsets, or even life. At least that’s the theory.
Sometimes we refer to our neighboring planets as having the “Goldilocks syndrome.” Mars and Venus are our cosmic neighbors, and together, we three planets all orbit within a distance from the sun called the “habitable zone,” where the amount of solar radiation reaching the surface is conducive for reasonable temperatures. So why did earth alone develop life, so prolifically and thoroughly that not even cataclysmic events could completely wipe it out? And what went wrong with our neighbors?
Venus is a study in what can go wrong with a nice planet. Venus and earth have plenty in common. They are very close in size, composition and their distance from the sun. However, Venus ended up with a very big problem: a runaway greenhouse effect. The effect of atmosphere trapping solar radiation and making a planet warmer than it should be is common- earth and Mars also have it. However, perhaps because it gets more solar radiation or because it had more carbon dioxide in its atmosphere, Venus is in a vicious cycle where its thick clouds trap nearly all the sunlight coming in. It simply cannot cool itself off. As we raise the level of certain gasses in our own atmosphere, we run the risk of having our greenhouse effect go astray. The current warming trend of our planet is a giant red flag that we are indeed starting a process that we would not be able to stop, much less reverse.
Mars, due to its further distance from the sun or its diminutive size, has too little atmosphere, and thus too little greenhouse effect. It is too cold on the surface of Mars for water to exist in liquid form, so it ended up a dry, cold desert-like planet. We know that Mars once was warmer and are convinced that water used to flow, but unless the conditions are just right, a planet goes awry and climate changes ensue.
The newly discovered Goldilocks planet is orbiting a red dwarf star called Gliese 581, about 20 light years away. The planet is heavier than earth, with a rocky surface and most likely liquid water. That’s a lot of information about this planet, since the data they gathered is mostly about how Gliese 581 wobbles. From this wobble, astronomers can glean information about what is going around the star to make it wobble. They infer size, distance, and even composition from the wobble. They have surmised that Gliese’s planet may be very much like earth, perhaps a “just right” place where water and life could exist. However, as we look at our neighboring planets, we see a lot of variation in a planet’s fate. It will be interesting to learn more about these extra-solar planets. Even if we don’t find life, perhaps we will find answers to how planets behave, giving us insight to our own problems and possible solutions.
Until next week, my friends, enjoy the view.
by C. Zaitz
The news is that astronomers have found a new planet orbiting a distant star. Astronomers have been finding planets in distant solar systems for decades, but usually the planets they discover are huge, more like Jupiter on steroids than anything earth-like. With better telescopes and more research, we are beginning to see the smaller planets. One in particular is being heralded as a “Goldilocks” planet, not too big, not too small, nor too cold, nor too hot. A “just right” planet that could possibly harbor liquid water, pretty sunsets, or even life. At least that’s the theory.
Sometimes we refer to our neighboring planets as having the “Goldilocks syndrome.” Mars and Venus are our cosmic neighbors, and together, we three planets all orbit within a distance from the sun called the “habitable zone,” where the amount of solar radiation reaching the surface is conducive for reasonable temperatures. So why did earth alone develop life, so prolifically and thoroughly that not even cataclysmic events could completely wipe it out? And what went wrong with our neighbors?
Venus is a study in what can go wrong with a nice planet. Venus and earth have plenty in common. They are very close in size, composition and their distance from the sun. However, Venus ended up with a very big problem: a runaway greenhouse effect. The effect of atmosphere trapping solar radiation and making a planet warmer than it should be is common- earth and Mars also have it. However, perhaps because it gets more solar radiation or because it had more carbon dioxide in its atmosphere, Venus is in a vicious cycle where its thick clouds trap nearly all the sunlight coming in. It simply cannot cool itself off. As we raise the level of certain gasses in our own atmosphere, we run the risk of having our greenhouse effect go astray. The current warming trend of our planet is a giant red flag that we are indeed starting a process that we would not be able to stop, much less reverse.
Mars, due to its further distance from the sun or its diminutive size, has too little atmosphere, and thus too little greenhouse effect. It is too cold on the surface of Mars for water to exist in liquid form, so it ended up a dry, cold desert-like planet. We know that Mars once was warmer and are convinced that water used to flow, but unless the conditions are just right, a planet goes awry and climate changes ensue.
The newly discovered Goldilocks planet is orbiting a red dwarf star called Gliese 581, about 20 light years away. The planet is heavier than earth, with a rocky surface and most likely liquid water. That’s a lot of information about this planet, since the data they gathered is mostly about how Gliese 581 wobbles. From this wobble, astronomers can glean information about what is going around the star to make it wobble. They infer size, distance, and even composition from the wobble. They have surmised that Gliese’s planet may be very much like earth, perhaps a “just right” place where water and life could exist. However, as we look at our neighboring planets, we see a lot of variation in a planet’s fate. It will be interesting to learn more about these extra-solar planets. Even if we don’t find life, perhaps we will find answers to how planets behave, giving us insight to our own problems and possible solutions.
Until next week, my friends, enjoy the view.
Tuesday, April 24, 2007
Super Massive Black Holes
4/22/07 – 4/28/07
by C. Zaitz
One of the more eyebrow-raising bits of gossip heard in astronomy circles is that most galaxies, even our own, contain a super massive black hole at their cores. A super massive black hole is much heavier than a garden variety stellar black hole, which can weigh as little as one and a half suns or as much as 14 suns. That may not sound spectacular, but a black hole with the mass of 10 suns could fit into the city of Detroit. The mass of a black hole is directly related to its size, so the heavier it is, the bigger it is. But how massive is super massive?
The monster black holes we find in the centers of galaxies tend to range in mass from a hundred thousands suns to tens of billions of suns. Some scientists suggest that they started out the same way stellar-sized holes do, but over long periods of time grew larger and larger from consuming the available material in the center of the galaxy. It seems more likely that these black holes, like the one in the middle of our galaxy, formed from a large cloud of collapsing gas, creating a massive central star, some hundreds of thousands of solar masses, which then collapsed (with no supernova) to form a gigantic black hole. Since that time it has been eating everything close enough to be drawn in. Don’t worry, though; we are very, very far from the center of our galaxy, and not in the least affected by it.
We noted that the mass of the hole is directly related to its size, but it turns out that the density of a black hole is inversely related to its mass. The bigger the original star, the less dense it needs to be to become a black hole. Super massive black holes can actually be about as dense as water, since they are so very massive. And the event horizon, the place beyond which we lose sight of you as you swirl in, is so far from the singularity at the center that a trip into the super massive black hole would take enough time to allow you to ponder your fate. In fact, scientists think that the tidal forces normally so very strong near a black hole, strong enough to “spaghettify” you (your atoms are ripped into a long strand of you as you twirl into the hole) are not so strong near the really massive black holes. So your trip into it might be somewhat non-eventful, if not pleasant. That is, if you were to be so foolish to be near such a black hole. Lest we forget, there are many dangerous things about black holes, not the least of which is the torrent of X-rays and gamma rays flooding out of the accretion disk. This is the plate of material feeding into the black hole, and it really does look like a big, gassy plate, serving up the special of the day.
If you’d like to try to see the black hole at the center of our galaxy, you will have to imagine it, for it’s shrouded by millions of stars, clouds of gas and dark nebula forming a curtain in front of it. Even if there was no curtain, you’d still be hard pressed to see it, since no light can escape their gravitational pull, making them earn their nefarious reputations of the invisible gas-eating monsters in space.
Until next week, my friends, enjoy the view.
by C. Zaitz
One of the more eyebrow-raising bits of gossip heard in astronomy circles is that most galaxies, even our own, contain a super massive black hole at their cores. A super massive black hole is much heavier than a garden variety stellar black hole, which can weigh as little as one and a half suns or as much as 14 suns. That may not sound spectacular, but a black hole with the mass of 10 suns could fit into the city of Detroit. The mass of a black hole is directly related to its size, so the heavier it is, the bigger it is. But how massive is super massive?
The monster black holes we find in the centers of galaxies tend to range in mass from a hundred thousands suns to tens of billions of suns. Some scientists suggest that they started out the same way stellar-sized holes do, but over long periods of time grew larger and larger from consuming the available material in the center of the galaxy. It seems more likely that these black holes, like the one in the middle of our galaxy, formed from a large cloud of collapsing gas, creating a massive central star, some hundreds of thousands of solar masses, which then collapsed (with no supernova) to form a gigantic black hole. Since that time it has been eating everything close enough to be drawn in. Don’t worry, though; we are very, very far from the center of our galaxy, and not in the least affected by it.
We noted that the mass of the hole is directly related to its size, but it turns out that the density of a black hole is inversely related to its mass. The bigger the original star, the less dense it needs to be to become a black hole. Super massive black holes can actually be about as dense as water, since they are so very massive. And the event horizon, the place beyond which we lose sight of you as you swirl in, is so far from the singularity at the center that a trip into the super massive black hole would take enough time to allow you to ponder your fate. In fact, scientists think that the tidal forces normally so very strong near a black hole, strong enough to “spaghettify” you (your atoms are ripped into a long strand of you as you twirl into the hole) are not so strong near the really massive black holes. So your trip into it might be somewhat non-eventful, if not pleasant. That is, if you were to be so foolish to be near such a black hole. Lest we forget, there are many dangerous things about black holes, not the least of which is the torrent of X-rays and gamma rays flooding out of the accretion disk. This is the plate of material feeding into the black hole, and it really does look like a big, gassy plate, serving up the special of the day.
If you’d like to try to see the black hole at the center of our galaxy, you will have to imagine it, for it’s shrouded by millions of stars, clouds of gas and dark nebula forming a curtain in front of it. Even if there was no curtain, you’d still be hard pressed to see it, since no light can escape their gravitational pull, making them earn their nefarious reputations of the invisible gas-eating monsters in space.
Until next week, my friends, enjoy the view.
Wednesday, April 11, 2007
Black, Black Holes
4/15/07 – 4/21/07
by C. Zaitz
One of the strangest, most compelling objects in the universe are black holes. The idea that something can be so powerful, so destructive, and yet invisible to us is very compelling. Ever since they were first speculated to exist, we have been searching the skies for the invisible monsters, the star-eating, gas-sucking anomalies of nature.
At first, it was very hard to find black holes. You have to get creative; you have to find something that the black hole is affecting. It’s like looking for the skunk that gets into your garbage every night. You can’t see it; it’s dark and you’re looking in the night, but skunks certainly leave clues behind. So we try to “sniff out” black holes, and look for the destruction they cause.
One of the best indicators of the presence of a black hole is a binary star system that emits X-rays. Binary star systems are quite common in the galaxy, and it turns out that often, one star is much bigger than the other. Big stars, like Elvis, tend to burn very brightly and burn out quickly. When massive stars die, they often become black holes. The companion star still orbits the “hole” left behind, but if material from the companion star happens to get too close to the black hole, it will get swirled in and “eaten,” streaming out X-rays as tidal forces ionize the infalling gas. We see the X-rays, and can begin to pinpoint the black hole.
There are different sizes of black holes, but the most familiar are the ones that come from big stars, like the star in the shoulder of Orion called Betelgeuse (commonly pronounced “beetle-juice” to the delight of untold numbers of elementary students.) Betelgeuse is said to be bigger than the orbit of Mars. When such a massive star dies, it generally ends up in one of the most spectacular events in the universe, a supernova explosion. Most of the mass of the star is violently distributed into space as giant clouds of hot, colorful gas. But the core of the star remains, is still very massive, and has no means to keep it from collapsing. It begins a journey that no force in nature can hinder, and it only stops until all that once was the star is found in one single point - the singularity.
One curious thing about black holes is their affinity for infinity. Laws of physics, as we know them, start to get wobbly when we get close to the “singularity.” This is the point at which what used to be matter has collapsed to a single point. This is very hard to imagine. How can a lot of stuff, with a lot of mass and gravity, collapse into a single point? And how big is that point?
Einstein’s theory of general relativity tells us that at the singularity, all the core’s mass is compressed into a space with zero volume, while its density and gravity are infinitely big! But quantum physics, with its uncertainly principle, says more reasonably that it’s a very large amount of matter squeezed into the smallest possible amount of space. Still, it’s a pretty quirky concept. Perhaps that’s why they are so very interesting.
Next week, we will talk about the even more curious super-massive black holes. Meanwhile, enjoy lovely Venus in the sunset and Saturn crossing the southern skies all night long.
Until next week, my friends, enjoy the view.
by C. Zaitz
One of the strangest, most compelling objects in the universe are black holes. The idea that something can be so powerful, so destructive, and yet invisible to us is very compelling. Ever since they were first speculated to exist, we have been searching the skies for the invisible monsters, the star-eating, gas-sucking anomalies of nature.
At first, it was very hard to find black holes. You have to get creative; you have to find something that the black hole is affecting. It’s like looking for the skunk that gets into your garbage every night. You can’t see it; it’s dark and you’re looking in the night, but skunks certainly leave clues behind. So we try to “sniff out” black holes, and look for the destruction they cause.
One of the best indicators of the presence of a black hole is a binary star system that emits X-rays. Binary star systems are quite common in the galaxy, and it turns out that often, one star is much bigger than the other. Big stars, like Elvis, tend to burn very brightly and burn out quickly. When massive stars die, they often become black holes. The companion star still orbits the “hole” left behind, but if material from the companion star happens to get too close to the black hole, it will get swirled in and “eaten,” streaming out X-rays as tidal forces ionize the infalling gas. We see the X-rays, and can begin to pinpoint the black hole.
There are different sizes of black holes, but the most familiar are the ones that come from big stars, like the star in the shoulder of Orion called Betelgeuse (commonly pronounced “beetle-juice” to the delight of untold numbers of elementary students.) Betelgeuse is said to be bigger than the orbit of Mars. When such a massive star dies, it generally ends up in one of the most spectacular events in the universe, a supernova explosion. Most of the mass of the star is violently distributed into space as giant clouds of hot, colorful gas. But the core of the star remains, is still very massive, and has no means to keep it from collapsing. It begins a journey that no force in nature can hinder, and it only stops until all that once was the star is found in one single point - the singularity.
One curious thing about black holes is their affinity for infinity. Laws of physics, as we know them, start to get wobbly when we get close to the “singularity.” This is the point at which what used to be matter has collapsed to a single point. This is very hard to imagine. How can a lot of stuff, with a lot of mass and gravity, collapse into a single point? And how big is that point?
Einstein’s theory of general relativity tells us that at the singularity, all the core’s mass is compressed into a space with zero volume, while its density and gravity are infinitely big! But quantum physics, with its uncertainly principle, says more reasonably that it’s a very large amount of matter squeezed into the smallest possible amount of space. Still, it’s a pretty quirky concept. Perhaps that’s why they are so very interesting.
Next week, we will talk about the even more curious super-massive black holes. Meanwhile, enjoy lovely Venus in the sunset and Saturn crossing the southern skies all night long.
Until next week, my friends, enjoy the view.
Thursday, April 05, 2007
Orbiting Fun
4/1/07 – 4/7/07
One of my favorite websites is “Astronomy Picture of the Day” (APOD) - the images are just amazing. One recent image depicted the very slim crescent moon hanging above the blue-skied horizon of the earth. It was taken by the astronauts on the space station. I often forget that there are astronauts floating above the earth looking down on us every ninety minutes or so. In their free time they like to take pictures of the earth, and the one they took of the crescent moon is beautifully dream-like. Well, at least it made me day-dream when I saw it.
I thought about how fun it might be to toss little pebbles out the window and watch them burn up as they fall through the air and descend to earth. I would be creating my own meteors, and how fun is it that people on the earth below would look up and see my meteor shower. How many little children would be making wishes on the “falling stars” I was tossing down? Wouldn’t it be nice if there was a front porch on the International Space Station for visitors who are lucky enough to go up there? What a view from that porch swing!
Obviously I’m amusing myself with fanciful thoughts of being in orbit, but I bet someday it will come true. Why not? People pay lots of money for all sorts of exotic vacations, but what could be more exotic than a few weeks aboard the space station? Of course, it being a scientific endeavor, and being rather on the dangerous end of things, one should probably come up with a scientific experiment or two to make it worthwhile. It can’t be all solar-tanning windows and zero-g foot rubs. I think I would experiment with different fluids and how they behaved in space. I would be sure to bring along six-packs of various fluids, and perhaps some pretzels to interact with the fluids. I’d be interested to study the formation of bubbles on carbonated beverages floating in microgravity. I’d also study how the human body reacts to these carbonated beverages. I’ve seen pictures of the astronauts floating giant bubbles of liquid around the cabin, dodging and ducking to catch them in their mouths. I think that would be pretty fun, and I’m sure there’s some scientific value in it.
While I was up on the porch of the Space Station, I would be sure to take lots of photos. I’d try to capture a pebble falling through the air. I think it would look like a pebble for awhile, and then it would start to glow, and then I’d see a little blaze and then would see it no more. That’s my theory, but it would be fun to prove it. That’s what science is all about, right?
There is science going on up there. The astronauts have a barrage of experiments they tend, from growing protein crystals to live tissue cells. Life in low gravity is very different than anything the human body is used to. If we ever want to make trips to Mars or other planets, we need to learn how to counteract the atrophy of our muscles and the weakening of our bones. We have to learn how to maneuver in centrifuges which can simulate the effects of gravity. There’s a lot to learn about living in space, but I know that I’d be on the list of volunteers to spend spring break in orbit!
Until next week, my friends, enjoy the view.
One of my favorite websites is “Astronomy Picture of the Day” (APOD) - the images are just amazing. One recent image depicted the very slim crescent moon hanging above the blue-skied horizon of the earth. It was taken by the astronauts on the space station. I often forget that there are astronauts floating above the earth looking down on us every ninety minutes or so. In their free time they like to take pictures of the earth, and the one they took of the crescent moon is beautifully dream-like. Well, at least it made me day-dream when I saw it.
I thought about how fun it might be to toss little pebbles out the window and watch them burn up as they fall through the air and descend to earth. I would be creating my own meteors, and how fun is it that people on the earth below would look up and see my meteor shower. How many little children would be making wishes on the “falling stars” I was tossing down? Wouldn’t it be nice if there was a front porch on the International Space Station for visitors who are lucky enough to go up there? What a view from that porch swing!
Obviously I’m amusing myself with fanciful thoughts of being in orbit, but I bet someday it will come true. Why not? People pay lots of money for all sorts of exotic vacations, but what could be more exotic than a few weeks aboard the space station? Of course, it being a scientific endeavor, and being rather on the dangerous end of things, one should probably come up with a scientific experiment or two to make it worthwhile. It can’t be all solar-tanning windows and zero-g foot rubs. I think I would experiment with different fluids and how they behaved in space. I would be sure to bring along six-packs of various fluids, and perhaps some pretzels to interact with the fluids. I’d be interested to study the formation of bubbles on carbonated beverages floating in microgravity. I’d also study how the human body reacts to these carbonated beverages. I’ve seen pictures of the astronauts floating giant bubbles of liquid around the cabin, dodging and ducking to catch them in their mouths. I think that would be pretty fun, and I’m sure there’s some scientific value in it.
While I was up on the porch of the Space Station, I would be sure to take lots of photos. I’d try to capture a pebble falling through the air. I think it would look like a pebble for awhile, and then it would start to glow, and then I’d see a little blaze and then would see it no more. That’s my theory, but it would be fun to prove it. That’s what science is all about, right?
There is science going on up there. The astronauts have a barrage of experiments they tend, from growing protein crystals to live tissue cells. Life in low gravity is very different than anything the human body is used to. If we ever want to make trips to Mars or other planets, we need to learn how to counteract the atrophy of our muscles and the weakening of our bones. We have to learn how to maneuver in centrifuges which can simulate the effects of gravity. There’s a lot to learn about living in space, but I know that I’d be on the list of volunteers to spend spring break in orbit!
Until next week, my friends, enjoy the view.
Wednesday, March 21, 2007
Of Great Magnitude
3/25/07 – 3/31/07
by C. Zaitz
“Star light, star bright, first star I see tonight…” so which one will it be? People often ask, “what’s the first star?” or “what’s the biggest star?” or my personal favorite, “what’s the farthest star?” These questions tend to our desire to catalogue things, rank them, sort and classify. Maybe knowing the biggest, best, and brightest may be a way to make sense of the infinite and chaotic universe.
The problem with far away stars is that they are really hard to see! At the very limit of our view lie the most distant objects we can see; the quasars, with their light so stretched from the billions of years of travel that their spectra have migrated far into the red and infrared extremes. Quasars are strange objects; compact, bright and very distant. They seem to be the cores of ancient galaxies, most certainly with giant black holes at their centers. As of now, the farthest quasar we’ve found is nearly 13 billion light years away. That’s close to the time when we think the first stars and galaxies were forming. Before that, there was no light at all. So we’ll have to be content to say quasars are the farthest “objects” we can see.
What about big? All stars are big, compared to earth. Maybe you’ve heard that the sun a small star. In the great scheme of things, perhaps it’s not as big as, say, Betelgeuse or Deneb, but it’s just right for us. However, there are vast numbers of loftier and heftier stars than our own. Most of the bright stars in the sky would dwarf our sun. They are bright mainly because they are huge. We call the brightness of a star its magnitude. Stars have two magnitudes; the one we see, called the apparent magnitude, and the one it really is, called the absolute magnitude. Imagine trying to compare sizes of sailboats in a lake. It would be easy if they were all the same distance from you, but they’re all over the lake. You could classify them by how big they look, but that’s not really fair for the ones far away- they’ll always look tiny. Unfortunately, it’s very tricky to find the absolute magnitude of stars since they are scattered all over the universe. With sailboats, you might be able to recognize the type of boat by its appearance and infer its size from that knowledge, and that’s what we do with stars. But there’s room for error- what if the same brand of boat comes in 24’ and 32’ and they look very similar? Astronomers have several methods of estimating size and distance, but it’s not an exact science. So we’ll just say that Epsilon Aurigae, in the constellation of Auriga, is 2,700 times bigger than our sun, and that’s one of the biggest we’ve ever seen.
So how does one decide what the first star is? Are we looking for the first star that you see in the evening sky? This answer can be evasive, since the first star is usually a planet. Planets can be very bright, especially Venus. Venus has been greeting the sunset lately, and as twilight fades, its brilliance in the western sky is unparalleled. But it’s not a star. However, when you’re looking for the first of anything in the night sky, look for Venus. Its apparent magnitude is very great, and when it comes to just enjoying the night sky, appearances can be everything!
Until next week, my friends, enjoy the view.
by C. Zaitz
“Star light, star bright, first star I see tonight…” so which one will it be? People often ask, “what’s the first star?” or “what’s the biggest star?” or my personal favorite, “what’s the farthest star?” These questions tend to our desire to catalogue things, rank them, sort and classify. Maybe knowing the biggest, best, and brightest may be a way to make sense of the infinite and chaotic universe.
The problem with far away stars is that they are really hard to see! At the very limit of our view lie the most distant objects we can see; the quasars, with their light so stretched from the billions of years of travel that their spectra have migrated far into the red and infrared extremes. Quasars are strange objects; compact, bright and very distant. They seem to be the cores of ancient galaxies, most certainly with giant black holes at their centers. As of now, the farthest quasar we’ve found is nearly 13 billion light years away. That’s close to the time when we think the first stars and galaxies were forming. Before that, there was no light at all. So we’ll have to be content to say quasars are the farthest “objects” we can see.
What about big? All stars are big, compared to earth. Maybe you’ve heard that the sun a small star. In the great scheme of things, perhaps it’s not as big as, say, Betelgeuse or Deneb, but it’s just right for us. However, there are vast numbers of loftier and heftier stars than our own. Most of the bright stars in the sky would dwarf our sun. They are bright mainly because they are huge. We call the brightness of a star its magnitude. Stars have two magnitudes; the one we see, called the apparent magnitude, and the one it really is, called the absolute magnitude. Imagine trying to compare sizes of sailboats in a lake. It would be easy if they were all the same distance from you, but they’re all over the lake. You could classify them by how big they look, but that’s not really fair for the ones far away- they’ll always look tiny. Unfortunately, it’s very tricky to find the absolute magnitude of stars since they are scattered all over the universe. With sailboats, you might be able to recognize the type of boat by its appearance and infer its size from that knowledge, and that’s what we do with stars. But there’s room for error- what if the same brand of boat comes in 24’ and 32’ and they look very similar? Astronomers have several methods of estimating size and distance, but it’s not an exact science. So we’ll just say that Epsilon Aurigae, in the constellation of Auriga, is 2,700 times bigger than our sun, and that’s one of the biggest we’ve ever seen.
So how does one decide what the first star is? Are we looking for the first star that you see in the evening sky? This answer can be evasive, since the first star is usually a planet. Planets can be very bright, especially Venus. Venus has been greeting the sunset lately, and as twilight fades, its brilliance in the western sky is unparalleled. But it’s not a star. However, when you’re looking for the first of anything in the night sky, look for Venus. Its apparent magnitude is very great, and when it comes to just enjoying the night sky, appearances can be everything!
Until next week, my friends, enjoy the view.
Tuesday, March 13, 2007
What Goes Around
3/18/07 – 3/24/07
by C. Zaitz
I’ve been giving a series of planetarium shows for fourth graders. I’ve heard a lot of interesting things come out of ten year olds, but today they stumped me. I was pointing out the planets that are visible in the early evening. Venus hovers above the sunset, driving light daggers into your eyes as you watch the glow of the sun fade. Saturn, however, lags behind and is only just rising to a nice height at sunset. It is in the southeast, whereas Venus is definitely following the sun into the west.
I told the fourth graders that it was 8:30 at night and I showed them the two planets. Then I asked them where Venus would be by 10pm. They were a verbal group with stretch marks in their armpits from raising their hands so much. I assumed they would say that Venus would go down in the west, like the sun, moon and all the stars. It seemed like a safe question.
Not so. Among the answers I got were, “it will go to the north,” “it will go back to the east” and “it will go south.” I could not BRIBE them to say it went down in the west. So I asked them what was really moving when the sun went down.
We talked through the rotation of the earth and I told them that we are spinning at 800 mph in Michigan. I asked them why they thought we couldn’t feel that motion and we talked about the reasons, such as the fact that we’ve always been spinning on the big earth and as long as it doesn’t speed up or stop, we will never notice its motion. Then to top it all off, I basically pirouetted until I got dizzy to illustrate the motion of the earth. That was my big wind-up. Then I threw it back to them. With excited, baited breath I asked, “So where will Venus be in an hour, my young friends?” I was sure that my antics and explanations had done the trick. But it hadn’t. Not even close. Somehow those young minds had heard or read something that had confused them about the motion of sky objects. And I didn’t know how to undo it.
So I laughed it off and we moved on. Later on the time came to actually move the stars toward the west. I took the opportunity to try once more, so I pointed to Venus and had them watch it as it sank down into the western horizon. I think they saw it. They looked surprised, but I think they finally believed that Venus would follow the sun down in the west. Sometimes seeing is believing. I know that the concept of the earth spinning is pretty abstract, and ten year olds aren’t quite abstract thinkers yet, but I thought that they might have noticed things setting in the west. When I realized they may never have actually seen Venus in the sky, I got a little sad. So to all of you with kids, take them out this month and show them Venus. Just point yourself toward the west at sunset and you’ll see it, clouds willing. And if you have a few moments later on, spy on it again and see where it went. I’m pretty sure that it will have followed the sun down in the west. But it’s always good to see it for yourself.
Until next week, my friends, enjoy the view.
by C. Zaitz
I’ve been giving a series of planetarium shows for fourth graders. I’ve heard a lot of interesting things come out of ten year olds, but today they stumped me. I was pointing out the planets that are visible in the early evening. Venus hovers above the sunset, driving light daggers into your eyes as you watch the glow of the sun fade. Saturn, however, lags behind and is only just rising to a nice height at sunset. It is in the southeast, whereas Venus is definitely following the sun into the west.
I told the fourth graders that it was 8:30 at night and I showed them the two planets. Then I asked them where Venus would be by 10pm. They were a verbal group with stretch marks in their armpits from raising their hands so much. I assumed they would say that Venus would go down in the west, like the sun, moon and all the stars. It seemed like a safe question.
Not so. Among the answers I got were, “it will go to the north,” “it will go back to the east” and “it will go south.” I could not BRIBE them to say it went down in the west. So I asked them what was really moving when the sun went down.
We talked through the rotation of the earth and I told them that we are spinning at 800 mph in Michigan. I asked them why they thought we couldn’t feel that motion and we talked about the reasons, such as the fact that we’ve always been spinning on the big earth and as long as it doesn’t speed up or stop, we will never notice its motion. Then to top it all off, I basically pirouetted until I got dizzy to illustrate the motion of the earth. That was my big wind-up. Then I threw it back to them. With excited, baited breath I asked, “So where will Venus be in an hour, my young friends?” I was sure that my antics and explanations had done the trick. But it hadn’t. Not even close. Somehow those young minds had heard or read something that had confused them about the motion of sky objects. And I didn’t know how to undo it.
So I laughed it off and we moved on. Later on the time came to actually move the stars toward the west. I took the opportunity to try once more, so I pointed to Venus and had them watch it as it sank down into the western horizon. I think they saw it. They looked surprised, but I think they finally believed that Venus would follow the sun down in the west. Sometimes seeing is believing. I know that the concept of the earth spinning is pretty abstract, and ten year olds aren’t quite abstract thinkers yet, but I thought that they might have noticed things setting in the west. When I realized they may never have actually seen Venus in the sky, I got a little sad. So to all of you with kids, take them out this month and show them Venus. Just point yourself toward the west at sunset and you’ll see it, clouds willing. And if you have a few moments later on, spy on it again and see where it went. I’m pretty sure that it will have followed the sun down in the west. But it’s always good to see it for yourself.
Until next week, my friends, enjoy the view.
Wednesday, March 07, 2007
Moon Dust
by C. Zaitz
I’ve been thinking a lot lately about dust. Not just the dust that accumulates on the piano or the blinds. Not even the dust mixes with my shedding dog’s hair and ends up big as my fist, rolling across the hardwood floor. No, I’ve been thinking of far away dust, the kind of dust that sheaths the moon.
I have the privilege of working with some students who are involved in special projects. One student is trying to measure the electrical charge of dust that has been exposed to ultraviolet light. She chose this project because it seems that dust on the moon is very clingy. Astronauts who went to the moon and walked around got very dirty, very quickly. As soon as they stepped on the dust, it jumped onto their spacesuits and clung for dear life, almost as if the little dust particles had been waiting for billions of years for a ride to earth and finally it saw the opportunity. She wanted to see how charged dust can get, even here on earth. In that process we’ve both been learning a lot about dust. It’s not very sexy, but it’s pretty important.
Moon dust has some interesting properties. It’s not like the soft dust we find around the house. That dust is made of flakes of skin, pet dander, dirt particles and lint, among other things. Moon dust, however, is craggy and jagged. It’s made when asteroids hit the moon and pulverize rock. There’s nothing soft about moon dust. It’s so sharp that it cut through the seals on containers used to carry it back to earth. You wouldn’t want to step on a dust ball made of moon dust.
One of the problems with moon dust, and even dust on Mars, is that it tends to cling to everything. Scientists have different ideas why. One of the most popular ideas is something we experience all the time; static electricity, or better said, a difference in charges. Think of that dust that collects on your TV screen. The screen gets charged when it’s on, and the neutral dust gets attracted to it. Now think of the moon’s surface. Radiation from the sun knocks electrons off the dust and the particles become charged. Once an astronaut walks through the dust, the difference in charge makes the dust veritably leap onto the astronaut’s spacesuit. Since the dust is so caustic, in time it can cut and poke into the skin of the spacesuit, which is the only thing protecting the astronaut from certain death in the lunar environment. The dust is carried into the lunar lander and can get into sensitive equipment, with the potential of causing disaster.
Studies on how to combat the “stickiness” of the dust and the potential harm from it ended with the Apollo missions, but the rovers on Mars are still hampered by Martian dust as it covers their solar panels and gets into the working parts. It turns out that lowly dust can be a very important issue in future space travel. It could also be a key into understanding how the solar system formed, since current theories imply that the sun and planets coalesced out of space dust and gas. Dust has been around a long time. Perhaps with further study, we will know how to deal with moon dust by the time we get there in 2018. I know I wouldn’t want moon dust ruining my trip to the moon!
Until next week, my friends, enjoy the view.
I’ve been thinking a lot lately about dust. Not just the dust that accumulates on the piano or the blinds. Not even the dust mixes with my shedding dog’s hair and ends up big as my fist, rolling across the hardwood floor. No, I’ve been thinking of far away dust, the kind of dust that sheaths the moon.
I have the privilege of working with some students who are involved in special projects. One student is trying to measure the electrical charge of dust that has been exposed to ultraviolet light. She chose this project because it seems that dust on the moon is very clingy. Astronauts who went to the moon and walked around got very dirty, very quickly. As soon as they stepped on the dust, it jumped onto their spacesuits and clung for dear life, almost as if the little dust particles had been waiting for billions of years for a ride to earth and finally it saw the opportunity. She wanted to see how charged dust can get, even here on earth. In that process we’ve both been learning a lot about dust. It’s not very sexy, but it’s pretty important.
Moon dust has some interesting properties. It’s not like the soft dust we find around the house. That dust is made of flakes of skin, pet dander, dirt particles and lint, among other things. Moon dust, however, is craggy and jagged. It’s made when asteroids hit the moon and pulverize rock. There’s nothing soft about moon dust. It’s so sharp that it cut through the seals on containers used to carry it back to earth. You wouldn’t want to step on a dust ball made of moon dust.
One of the problems with moon dust, and even dust on Mars, is that it tends to cling to everything. Scientists have different ideas why. One of the most popular ideas is something we experience all the time; static electricity, or better said, a difference in charges. Think of that dust that collects on your TV screen. The screen gets charged when it’s on, and the neutral dust gets attracted to it. Now think of the moon’s surface. Radiation from the sun knocks electrons off the dust and the particles become charged. Once an astronaut walks through the dust, the difference in charge makes the dust veritably leap onto the astronaut’s spacesuit. Since the dust is so caustic, in time it can cut and poke into the skin of the spacesuit, which is the only thing protecting the astronaut from certain death in the lunar environment. The dust is carried into the lunar lander and can get into sensitive equipment, with the potential of causing disaster.
Studies on how to combat the “stickiness” of the dust and the potential harm from it ended with the Apollo missions, but the rovers on Mars are still hampered by Martian dust as it covers their solar panels and gets into the working parts. It turns out that lowly dust can be a very important issue in future space travel. It could also be a key into understanding how the solar system formed, since current theories imply that the sun and planets coalesced out of space dust and gas. Dust has been around a long time. Perhaps with further study, we will know how to deal with moon dust by the time we get there in 2018. I know I wouldn’t want moon dust ruining my trip to the moon!
Until next week, my friends, enjoy the view.
Wednesday, February 28, 2007
Astarte’s Crescent
3/4/07 – 3/10/07
by C. Zaitz
The crescent may very well be one of the most beautiful shapes of our lovely neighbor, the moon. The curved smile of the young moon after it has just passed through its shadowy new phase is a crowning jewel to twilight’s glorious robes of color, but sometimes that shadowy grin looks like a smirk, and sometimes a friendly smile.
Sometimes when you look at the crescent moon, it appears to look like the letter “C”, only backwards, more like a “D” without the straight part. But sometimes it looks like the letter “U,” or a birch bark canoe sailing over the horizon before it dips below the earth. I saw the moon looking like that last month, and I wondered about it.
It was an unusual sight. I wasn’t used to seeing the crescent moon in that position, and strangely I had just read an article about how the crescent moon looks like a “U” from latitudes near the equator. So why was our crescent moon looking like that, at our latitude, nearly halfway to the North Pole?
It’s true that near the equator, the crescent waxing moon looks more like a boat than a banana. It sets nearly straight down, chasing the sun to the ground. The sun does the same thing; near the equator the sun rises nearly straight up and sets the same way. In Michigan, we only see that on the vernal or autumnal equinoxes, when the sun crosses the celestial equator (an imaginary projection of earth’s equator onto the sky.) We remember that earth is tipped 23.5 degrees with respect to the plane of our orbit around the sun. If we project the plane of our orbit out into space and also the equator, these two circles cross at two points. One is in the spring, and the other is in autumn. We call these two days the equinoxes, and we are coming up on the Vernal or spring equinox. It’s at this time of year that the sun rises due east and sets due west. The moon’s orbit is only tipped about 5 degrees from the plane of our orbit, so it’s following that path pretty closely. So if the sun seems to rise and set straight up at this time of the year, it stands to reason that the young moon would as well. Thus we see our smiling moon.
In ancient times the crescent moon was the symbol of the Phoenicians goddess Astarte, known as Ishtar to the Mesopotamians, Diana to the Greeks and Venus to the Romans. Her “bediamonded crescent” was poetically captured by Edgar Allan Poe. You can see the crescent moon in modern times on flags and images from many different cultures. Muslim holidays and religious observances often start or end with the first sighting of the waxing crescent moon. The optimal conditions for sighting the young moon is when the angle that the moon sets is nearly perpendicular to the horizon, which happens to be around mid March for the Northern Hemisphere. The next young crescent moon will appear a few days after new moon, so look around the 19th or 20th of March to see if you can spot it. If you don’t see it one night, look the next. You’ll see the slim crescent grow, night after night, and be a witness to one of the more beautiful sights in the sky.
Until next week, my friends, enjoy the view.
by C. Zaitz
The crescent may very well be one of the most beautiful shapes of our lovely neighbor, the moon. The curved smile of the young moon after it has just passed through its shadowy new phase is a crowning jewel to twilight’s glorious robes of color, but sometimes that shadowy grin looks like a smirk, and sometimes a friendly smile.
Sometimes when you look at the crescent moon, it appears to look like the letter “C”, only backwards, more like a “D” without the straight part. But sometimes it looks like the letter “U,” or a birch bark canoe sailing over the horizon before it dips below the earth. I saw the moon looking like that last month, and I wondered about it.
It was an unusual sight. I wasn’t used to seeing the crescent moon in that position, and strangely I had just read an article about how the crescent moon looks like a “U” from latitudes near the equator. So why was our crescent moon looking like that, at our latitude, nearly halfway to the North Pole?
It’s true that near the equator, the crescent waxing moon looks more like a boat than a banana. It sets nearly straight down, chasing the sun to the ground. The sun does the same thing; near the equator the sun rises nearly straight up and sets the same way. In Michigan, we only see that on the vernal or autumnal equinoxes, when the sun crosses the celestial equator (an imaginary projection of earth’s equator onto the sky.) We remember that earth is tipped 23.5 degrees with respect to the plane of our orbit around the sun. If we project the plane of our orbit out into space and also the equator, these two circles cross at two points. One is in the spring, and the other is in autumn. We call these two days the equinoxes, and we are coming up on the Vernal or spring equinox. It’s at this time of year that the sun rises due east and sets due west. The moon’s orbit is only tipped about 5 degrees from the plane of our orbit, so it’s following that path pretty closely. So if the sun seems to rise and set straight up at this time of the year, it stands to reason that the young moon would as well. Thus we see our smiling moon.
In ancient times the crescent moon was the symbol of the Phoenicians goddess Astarte, known as Ishtar to the Mesopotamians, Diana to the Greeks and Venus to the Romans. Her “bediamonded crescent” was poetically captured by Edgar Allan Poe. You can see the crescent moon in modern times on flags and images from many different cultures. Muslim holidays and religious observances often start or end with the first sighting of the waxing crescent moon. The optimal conditions for sighting the young moon is when the angle that the moon sets is nearly perpendicular to the horizon, which happens to be around mid March for the Northern Hemisphere. The next young crescent moon will appear a few days after new moon, so look around the 19th or 20th of March to see if you can spot it. If you don’t see it one night, look the next. You’ll see the slim crescent grow, night after night, and be a witness to one of the more beautiful sights in the sky.
Until next week, my friends, enjoy the view.
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