Monday, October 29, 2007

No Glass Ceiling

11/4/07 – 11/10/07

by C. Zaitz

When I was visiting my parents in Rochester, NY, I saw a headline in the local paper about Pamela Melroy, a retired US Air Force Colonel. She was a local girl, one of the very few female pilots who had made it successfully through the astronaut training program. She is only the second commander of the Space Shuttle, and most likely the last.

Melroy got degrees in physics and astronomy from Wellesley College, a female-only institution patterned after Mount Holyoke Seminary (College in 1893), the first of seven famous colleges for women. These so-called “seven sisters” were chartered in the late 1800s when women had little opportunity for the excellent education that men had from the so-called Ivy League schools. Currently only five of the seven are still private women’s colleges, but those five still strive to give women an excellent education and the self confidence of succeeding in often male-dominated fields. Apparently it worked for Pamela Melroy. As she herself said in a commencement address, “The environment gives women a place to dream without being restricted or blinded by culturally generated limits.”

One of a very select group of shuttle pilots, Melroy is definitely a minority at NASA. She is one of 18 female astronauts out of a group of 91. Strangely, and for the first time ever, she is one of the two women in charge on the current mission. While she commands the space shuttle Discovery, her colleague Peggy Whitson will serve as the Station Commander on board the International Space Station. The fact that for the first time in the 50 year history of spaceflight that two women will be commanding is a rare coincidence, NASA says. The fact is, Melroy is most likely the last shuttle commander, and the only female test pilot left at NASA.

The shuttle’s days are numbered. NASA is phasing out the shuttle in favor of an updated launch vehicle, Orion. From the first flight of the Columbia in 1981 to the recent launch of Discovery, the Space Transportation System, NASA’s official handle for the shuttle, has been an astoundingly reliable workhorse of our space program. Of the120 flights of the entire fleet, Discovery has flown 33 of them. However, the loss of even one vehicle means the loss of the astronauts within it. Out of the original five shuttles built, only three remain. Considering the danger of launching and landing such an unwieldy vehicle, the statistics of 2% death rate per astronaut-flight seem like a small risk. But each one of those twelve deaths in the two shuttle disasters was painful and very difficult to overcome.

It is the tragedy of loss that spurs us on to build a bigger and better space exploration vehicle. And it is the spirit of adventure and the willingness to risk her life that allows people like Pam Melroy to follow her dream against the odds to become an astronaut, and to command the Discovery.

The last trips planned for the remaining shuttles are in 2010. After that, Orion will take over for the return to the Moon and possibly one day to Mars. Astronaut tryouts are coming, and astronaut school begins in 2009, in case you want to clear your calendar!

Until next week, my friends, enjoy the view.

Wednesday, October 24, 2007

Core Issues

10/28 - 11/3
by C. Zaitz

I look up a lot, but right now my mind is on core issues, like what is at the core of our home planet. There has been conflict about this very question in the past. In the 17th century, the famous comet hunter Edmund Halley had a theory that the earth was actually hollow, and thought the core was luminous and filled with gas. Where did he get such a bright idea? From none other than his contemporary scientist, Isaac Newton. Newton had calculated the density of the earth, and had found that the center of the earth must be at least twice as dense as the surface. But he also calculated the density of the moon, and mistakenly found it much denser than the earth. Since there was no reason to suggest that the moon was made so much differently than the earth, Edmund Halley sought to explain the difference by suggesting that four-ninths of the earth was empty. He imagined the inner sphere inhabited by throngs of beings, as were all the planets of the solar system. He even had a portrait painted of himself as Astronomer Royal with a diagram of his hollow- shelled earth, forever immortalized. Luckily his comet became so famous that for the most part people have forgotten this aspect of his work. Some folks, however, took the idea of the hollow earth and elaborated, so vestiges of the theory still haunt society today.

Rather than being hollow at its core, Earth is actually quite dense. It is a rocky conglomeration, like the other inner planets, very close in nature to its sister, Venus. Earth and Venus are like twins, separated at birth. Venus has a different disposition than her sister. She’s very hot, with an atmosphere that would crush and melt any visiting earthlings. Earth is more subdued, and more gracious to the living beings that inhabit her outer skin.

Underneath the harsh exterior, Venus has a dense metallic core, similar to earth, with perhaps a liquid outer core surrounding it. On earth, this rotating liquid core generates our strong magnetic field, allowing us to navigate with compasses and protecting us from killing radiation from the sun. Venus seems to be lacking a magnetic field, though her makeup is similar to the earth. The difference may lie in the fact that Venus rotates slowly, and retrograde to the rest of the solar system. The slow rotation may not provide enough energy to generate a magnetic field.

So how do we know about the cores of the planets? On earth, no one has been more than 7.5 miles down. That’s not very far, considering that it would be a journey of 4,000 miles to reach the center. Most of what we know about the interior of the earth comes from seismic data. We can measure how fast earthquake shock waves travel through different materials, and estimate the depth and make-up of earth’s layers. That is how we found out about the liquid outer core of the earth. Seismic data doesn’t tell us everything, but it does rule out a society of folks living in a hollow earth.

As you ponder life at the center of a planet, you can spy Venus by looking toward the sunrise. She’ll be winking at you from the south eastern morning sky.

Until next week, my friends, enjoy the view.

Sunday, October 14, 2007


10/21/07 – 10/28/07
by C. Zaitz

Halloween is a great night, isn’t it? Modern culture has taken our holiday to new heights of materialism, but if we can get back to its former meaning, it can be a great night for communities. October often has cool, clear nights, great for viewing the sky. On Halloween, kids and parents are out, neighborhoods are active, and the sky darkens early. What better time to look up and notice the evocative sky? It can bring us together and remind us of our connection to the seasons and the sky above.

Halloween is the last of four special days of the year known as the cross-quarter days. These days are the midway points between the better known solstices and equinoxes. As the earth slips around the sun, it changes its tilt with respect to it. At this time of year, the earth is changing its orientation daily. The northern hemisphere leans toward the sun in the summer, but in winter it leans away from it. The leaning causes a big difference in weather. The sun doesn’t heat us as well now that we aren’t getting direct rays. The sun also makes a short path in the sky, which means it’s not in the sky as long. Shorter days and indirect rays cause winter here in the north. That, and that alone, causes our seasons.

We celebrated the first day of fall, the autumn equinox, on September 23rd this year, and winter begins officially on December 22nd, the winter solstice. But for many of us, fall doesn’t really get under way until October. Perhaps that’s why we have retained the celebration of the cross quarter day in this one season. Seasons on earth don’t really kick in until the earth itself is on board. It takes time for heating and cooling to take place, just like in the air conditioning and heating in your car. Our seasons are delayed so much that it seems like the cross-quarter days are really the "first days" of the season. It’s not a great leap to imagine October 31st as the end of the growing – harvest season. What better New Year’s Eve party than Halloween?

I like Halloween for one reason and one reason only: people are outside and looking at the sky. Ok, maybe that and the leftover candy! Halloween at the Zaitz house includes the traditional bowl of candy for trick-or-treaters, but also my trusty 4” Astroscan telescope, showing any and all comers a view of the sky. This year the moon will be past full by Halloween, so not very helpful in lighting our evening activities, but Jupiter will be shining powerfully in the southwest and showing its children- four of its tiny moons, visible through a telescope.

We have lost touch in our modern culture with most of the cross quarter days. The others are Groundhog’s Day in February, May Day, and Lammas day, in August. Halloween is by far the most famous of the cross quarter days, and the most fun. Halloween celebrations have lasted through the centuries. Pre-Christian Celts celebrated Samhain (“sau-wen”) as the end of the year/beginning of a new year. The association with death and dying has been preserved through the centuries in our modern celebration of Halloween. It’s the time of the year we can easily be in touch with the rhythms of the earth.

Until next week, my friends, enjoy the view.

Monday, October 08, 2007

Hot Hot Hot

From the nuclear furnace at the core to the extremely hot plasma of its corona, the sun is the definition of hot! Far from the “giant ball of fire” we learned about in first grade, it is more accurately described as a sphere of plasma. Plasma is not a common everyday household item. You know of plasma- lightning is an example. If you’ve seen the northern lights, you are seeing a colorful display of plasma. Plasma is hot, ionized gas.

The sun has plenty of plasma. Like other stars, it supports itself from the crushing weight of gravity by fusing hydrogen atoms at its core. Pressures and temperatures being what they are at the core of the sun, atoms that normally don’t like being all that close will overcome their repulsion and fuse together. In this process, they release prodigious amounts of energy.

It was actually the icon scientist Albert Einstein who quantified exactly how much energy in his uber-famous equation, E=mc (squared). In English, this equation says that you can get an enormous amount of energy out of a little bit of mass. The variable “c” stands for the speed of light, which is a pretty big quantity. And if you square it, it becomes super big. No matter how small your mass (m), if you multiply it by the speed of light squared, you have a very big number, which is E, the amount of energy you can get from it. This idea opened up a world of hurt.

Here on earth, we have harnessed the power of fission to unleash energy from an atom. We have figured out how to take a heavy element like uranium and “fission” it by tossing a neutron at it. By splitting a very heavy element like Uranium, we can release exorbitant amounts of energy. Unfortunately a by-product of the process is radioactive material, called “waste” due to its unpleasantness and difficulty of disposal without harm to humans. We use our knowledge for good, in our nuclear power plants, but also for bad, in our nuclear bombs. Hiroshima and Nagasaki both felt the power of unleashed of nuclear fission.

Stars don’t “fiss,” they fuse. Stars release energy through nuclear fusion. The sun isn’t filled with heavy elements like uranium. All they have at their disposal to keep alive is hydrogen. Luckily the universe decided that elements lighter than iron would be better off if they fused, rather than fissioned. The sun has lots of light elements to fuse, and it does so at will. This releases the life-giving energy that we receive some 93 million miles away. We seem to have a very advantageous spot in the solar system.

Think about toasting marshmallows on a stick. When you get too close to the fire, you end up with a crispy marshmallow that you have to snuff before popping into your mouth to hear the sizzle of your own saliva. If the marshmallow is too far from the fire, it remains cool and solid, not the most pleasing form of the food product. I find it both fascinating and reassuring that the earth maintains the place of the well-browned marshmallow. Not too close to the nuclear furnace, and not too far. It’s just right to keep us comfortable. So even with changing temperatures and seasons, we can be grateful for our place in space.

Sunday, October 07, 2007

Astarte and... Astarte

From Sunday morning, October 7th, 7am-ish.

The "too-poetical" poem of Edgar Allan Poe,


The skies they were ashen and sober;
The leaves they were crisped and sere -
The leaves they were withering and sere;
It was night in the lonesome October
Of my most immemorial year:
It was hard by the dim lake of Auber,
In the misty mid region of Weir -
It was down by the dank tarn of Auber,
In the ghoul-haunted woodland of Weir.

Here once, through and alley Titanic,
Of cypress, I roamed with my Soul -
Of cypress, with Psyche, my Soul.
These were days when my heart was volcanic
As the scoriac rivers that roll -
As the lavas that restlessly roll
Their sulphurous currents down Yaanek
In the ultimate climes of the pole -
That groan as they roll down Mount Yaanek
In the realms of the boreal pole.

Our talk had been serious and sober,
But our thoughts they were palsied and sere -
Our memories were treacherous and sere, -
For we knew not the month was October,
And we marked not the night of the year
(Ah, night of all nights in the year!) -
We noted not the dim lake of Auber
(Though once we had journeyed down here) -
Remembered not the dank tarn of Auber,
Nor the ghoul-haunted woodland of Weir.

And now, as the night was senescent
And star-dials pointed to morn -
As the star-dials hinted of morn -
At the end of our path a liquescent
And nebulous lustre was born,
Out of which a miraculous crescent
Arose with a duplicate horn -
Astarte's bediamonded crescent
Distinct with its duplicate horn.

And I said: "She is warmer than Dian;
She rolls through an ether of sighs -
She revels in a region of sighs:
She has seen that the tears are not dry on
These cheeks, where the worm never dies,
And has come past the stars of the Lion
To point us the path to the skies -
To the Lethean peace of the skies -
Come up, in despite of the Lion,
To shine on us with her bright eyes -
Come up through the lair of the Lion,
With love in her luminous eyes."

But Psyche, uplifting her finger,
Said: "Sadly this star I mistrust -
Her pallor I strangely mistrust:
Ah, hasten! -ah, let us not linger!
Ah, fly! -let us fly! -for we must."
In terror she spoke, letting sink her
Wings until they trailed in the dust -
In agony sobbed, letting sink her
Plumes till they trailed in the dust -
Till they sorrowfully trailed in the dust.

I replied: "This is nothing but dreaming:
Let us on by this tremulous light!
Let us bathe in this crystalline light!
Its Sybilic splendour is beaming
With Hope and in Beauty tonight! -
See! -it flickers up the sky through the night!
Ah, we safely may trust to its gleaming,
And be sure it will lead us aright -
We safely may trust to a gleaming,
That cannot but guide us aright,
Since it flickers up to Heaven through the night."

Thus I pacified Psyche and kissed her,
And tempted her out of her gloom -
And conquered her scruples and gloom;
And we passed to the end of the vista,
But were stopped by the door of a tomb -
By the door of a legended tomb;
And I said: "What is written, sweet sister,
On the door of this legended tomb?"
She replied: "Ulalume -Ulalume -
'Tis the vault of thy lost Ulalume!"

Then my heart it grew ashen and sober
As the leaves that were crisped and sere -
As the leaves that were withering and sere;
And I cried: "It was surely October
On this very night of last year
That I journeyed -I journeyed down here! -
That I brought a dread burden down here -
On this night of all nights in the year,
Ah, what demon hath tempted me here?
Well I know, now, this dim lake of Auber -
This misty mid region of Weir -
Well I know, now, this dank tarn of Auber,
This ghoul-haunted woodland of Weir."