Wednesday, September 27, 2006

Welcome Back

10/3/06 – 10/9/06
by C. Zaitz

I walked out with the dog the other morning and WHAM! There he was, the eye-catching Orion, sparkling clearer and bolder than I’d remembered from last spring when he faded into the sunset. He’d survived the summer hiding behind the sun and had finally made it to the morning sky. With his usual bravado he stole the show – who can think of faint Perseus when Orion is there? His faithful dogs were yipping at his ankles as usual; the Great Dog Canis Major with the brightest star Sirius as his wet nose, and above him the Little Dog, Canis Minor, with the bright star Procyon marking his tiny head.

In a few more months we will see Orion in the evening sky. But now his early morning appearance heralds the oncoming season of dying. He sneaks a step or two toward the west every day. Every step westward he takes brings us closer to winter.

Of course, it’s really the earth stepping toward Orion, not the other way around. We are swinging to the part of our orbit where we northerners are tipping away from the sun, and to where the distant stars of winter can be seen. Think of the last time you were on a merry-go-round. Pretend you’re the earth and the sun is at the center of the ride. If you turn in the saddle, (assuming you’re sitting on a wild zebra or maybe a unicorn) you look out toward people watching you. As you go around, you can wave at your friends standing there. Further around you see only strangers, laughing and pointing at you. Just once per rotation do you see friendly faces. That’s like the earth and Orion, or any other group of stars. Though the earth travels faster than a merry-go-round, it has quite a bit more distance to cover, so we can see the same constellations for months at a time as we orbit the sun. But when we see some groups, like our friend Orion, that necessarily means we won’t be able to see others, especially the ones on the other side of the sun from us like the Scorpion. That’s why we say that most constellations are seasonal, and Orion is a constellation of the winter season.

I had mixed emotions seeing Orion in the sky. Though he is a very magnificent constellation, he reminds me what is coming. It’s almost as if he brings the cold harshness of winter with him. It wasn’t always like that. Orion and his companion, Sirius, used to be the heralds of the wet season, or the flooding of the Nile river. To the Egyptians of long ago, the flooding of the Nile meant good things like irrigation, food and survival. It was so important to them, they based their calendar on Sirius’ rising.

The time when you first see morning rising of Sirius has been called the “dog days of summer.” This is generally the hottest part of the summer, usually August. But it is difficult to see Sirius when it’s so close to the sun. Now is the time to see it best in the morning sky. Even as the sun begins to paint the morning twilight in colors, Sirius and Orion still can shine through. Their cheerful glitter reminds us that winter does provide the best viewing for stars! And that is something to look forward to.

Until next week, my friends, enjoy the view!

Wednesday, September 20, 2006

Learning to Love It

9/26/06 – 10/2/06
By C. Zaitz

I’m taking a class called Environmental Interpretation. It’s like learning to be a guide at a park. We tramp around in the wet, dark woods of the Henry Ford Estate looking at plants, seeds, and berries. I consider myself an 8 on a scale of 1-10 for people who are curious about everything. The only reason I'm not a 9 or 10 is because of plants, seeds and berries. My challenge to myself is to see the beauty in ragweed, the artistry of a thistle and the genius of the black walnut. When I see a black walnut, all I can think of is how, as kids, we would collect black walnuts from the big trees in our yard and carefully place them in rows on the road. Bud the Driver would come lumbering down the street in the big yellow School Bus and run over the nuts with the giant bus tires. The squishy, popping sound delighted us, and the smelly, greasy black streak they made in the road created a glorious, terrible mess. Our hands were green and smelled like black walnuts for days. It was kid heaven.

Because of that experience, I always chuckle when I see a black walnut. But I don’t have any pleasant associations with ragweed or thistle. I don’t get a brain tickle when I think of marching through the wet grass to see it. I think about astronomy and how some people mentally yawn at the very thought of learning about the sky. The folks who are super-enthusiastic about plants must feel the same way I do about the stars. I find it hard to believe, but it must be true. Look how they get giddy talking about endozoochory seed dispersal. (That’s when a bird eats seeds and “disperses” them on your car.) Do I get that giddy when I talk about hydrostatic equilibrium, or the delicate balance in a star between gravity and radiation pressure? Egads, I believe I do!

On our latest march in the woods, we had the good fortune for the rain to stop long enough to see a lovely red-orange sunset in the west, paired with a Barbie-pink rainbow in the east. The sky was raging with color, the perfect antidote for my cold, wet soul. I’m a sky person. We all have our predilections, our tendency toward liking some things over others. I guess the key is to keep an open mind about subjects that don’t necessarily grab our fancy. Once I decided to enjoy the tramp, I was delighted by the wild orange impatiens, otherwise known as “touch me nots,” who’s spring-loaded seed pods exploded at a mere touch. I loved watching the huge heron glide over the pond in that glorious sunset, and marveled at the bats circling overhead in the enveloping dusk. I knew their little bat hearts were singing; there were so many mosquitoes, they could fill their bellies simply flying with their mouths open.

There was no chance of a moon or stars that evening. It was much too cloudy, but I imagined my friend Luna sailing high above us, and all the stars winking at me from behind the strato-nimbus curtain. I knew they’d still be there when I have more time to spend with them. Meanwhile I’m learning an important lesson: we can find things that interest us in just about everything if we are open to it. It’s a good lesson to learn.

Until next week, my friends, enjoy the view!

Wednesday, September 13, 2006

The Inconstant Moon

9/19/06 – 9/25/06
by C. Zaitz

I was in a class recently where we were given some questions on general science knowledge. One of the questions was, “explain why the moon has phases.” Inwardly I squealed with glee; I had trouble with two other quizzes I had taken that day, but I certainly can explain the moon’s phases.

It may seem like a general knowledge, but few people really know why the moon goes through phases. After twenty years of anecdotal experience in the planetarium, I have an opinion about why. Moon phases are taught in school at an age where it’s very difficult for kids to understand them. In third grade, most kids are still concrete learners and making the jump to an abstract view of the solar system is almost impossible. If they could hop on the Magic School Bus and go into space to watch the moon orbit the earth, they would have an accurate picture. But they cannot, and they have to rely on inadequate 2-D drawings and verbal explanations. Even 3-D models are not always helpful, since their inaccurate scales can introduce more misconceptions. In the absence of truly understanding these models, kids tend to make up their own explanations. Once these are made up, it’s very difficult in later life to counteract these ideas. So many adults still carry their childhood ideas about moon phases. Even some teachers!

I can tell you that moon phases are NOT caused by: 1. the earth’s shadow on the moon, 2. clouds covering part of the moon or 3. magic. The moon phases are caused by us seeing the illumination of the moon from different angles as it orbits us. Since the sun can only light half the moon at any given time, there are times when we look up at the moon and only see part of it illuminated. If it is opposite the sun from us, we can see the entire illuminated face. That’s Full Moon. But when the moon is in a different part of its orbit, we may see only a thin edge illuminated or an egg-shaped moon, not quite full. There are times when the moon lies somewhere between us and the sun. That is called New Moon; her illuminated side faces completely away from us. So where the moon is in its orbit around the earth determines what we see.

A logical question might be, “if the moon were between the earth and the sun, wouldn’t that make a solar eclipse?” Yes, it would, if the moon were precisely between the earth and sun. But the moon’s orbit is inclined to ours by about five degrees, making exact alignment rare. So rare, in fact, that the next solar eclipse visible from anywhere near Michigan will be on August 21, 2017. If you have family or friends in northern Oregon, Idaho, Wyoming, Nebraska, Missouri, Kentucky, Tennessee, North Carolina, Georgia, or South Carolina, now is a good time to secure their spare room. I anticipate a lot of excitement about a total solar eclipse in the heartland of the United States.

The dead, airless moon silently swings around the earth every month, completing its phases in 29.5 days. It waxes from the invisible New Moon to growing crescent, first quarter, bulging gibbous to Full Moon in about two weeks, and then it wanes through gibbous, last quarter, and finally crescent phase. The moon will be new on the 22nd, and every day after that you can begin to see the ever-so-lovely waxing crescent moon in the western sky at dusk.

Until next week, my friends, enjoy the view!

Friday, September 08, 2006

The Night Sky

You can now get your Night Sky in a variety of ways. You can read it here, as always, or tune into WHFR on Fridays from 10-11am to the WHFR Journal. The host, Mr. Jay Korinek, has invited me to read the column for the radio broadcast which will be turned to podcast or archived streamed broadcast, accessed through the website.

Wednesday, September 06, 2006

Expand Your Horizon

It's nearly autumn! It's the time of year when the scenery changes fairly quickly around us. Landscapes are mellowing and aging, turning different colors. Even the very stars in the sky are changing. Not only is the outdoor world changing, but things are changing inside, as well. Your local museums and planetaria have new programs to offer. Let’s take a look at what’s going on around us.

We’re beginning to notice the shortening length of day. The sun is sluggish rising, and before you know it, it’s fading off to the west to set. The summer triangle is still high overhead after sunset, but the constellations of autumn are seen at prime time- between 9pm and midnight. These are the constellations of Andromeda, Perseus and Pegasus.

Pegasus flies high across the southern sky, upside down and head first as always. Look for four stars high in the south in a great square shape, and you’ve most likely found Pegasus. The upper left hand star is a star called Alpheratz. Sometimes the star is also called “Sirrah.” The original Arabic name was “al-sirrah al-faras,” meaning “the navel of the horse.” The part that remains is “the horse” or al-faras (Alpheratz), but we all know it’s his belly button, Sirrah. It’s just funnier to remember. Andromeda looks like two long graceful antennae coming out of the bellybutton, which is an odd image, being that she’s a princess. In fact, if I were to verbally describe the constellations of fall to you, it would end up sounding quite strange. Perseus reminds me of a witch’s hat, and Cassiopeia the Queen looks like the letter “w” with a floppy leg on one end. Not a very graceful image for one of her stature. The king Cepheus is even worse; he looks like a miniature house ready to topple over.

The best way to learn the constellations is to visit your local planetarium. There you can not only learn about the stars, but also see pictures and hear stories that connect meaning to the star pictures. Plus you can meet other people who are interested in the world around them, and that is always a good adventure. The Vollbrecht Planetarium in Southfield offers day field trips as well as the excellent Friday night public show series by my colleague Mike Best, an expert entertainer -astronomer. His topics include neutron stars, black holes, asteroids, and the changing solar system. He’ll even talk about astrology and Pluto, poor Pluto. And you’ll always get Q&A time, handouts, and even door prizes. I will also be doing star shows there for schools and the public. Email me to book a show.

Cranbrook and the Detroit Science Center have excellent facilities, and you’ll always have fun there. But if you want a more personal tour of the sky, check out the smaller planetaria. The Henry Ford Community College Planetarium would be a great place to visit, and they will give shows for public and private groups. All these facilities can be found easily if you do a quick internet search for local planetaria, or even call 411 on your cell phone. I would love to get email from people interested in learning more about the night sky. This is a great time to try something new, to have a learning adventure, and to expand your horizon. Take advantage of the enthusiastic experts in your own neighborhood, take your kids or grandparents on an adventure, and maybe you’ll find out something new about the universe, or even better, about yourself!

Until next week, my friends, enjoy the view!