Mercury

Does this place look familiar? “Ah,” you say, “It looks like the Moon. The first astronauts set foot there in 1969.”

Yep, it does resemble the Moon, somewhat. But, this is Mercury — named after the Roman god of travel and business. LIke its namesake, it does get around — but is limited to orbiting around the Sun once every 88 days. At its closest, Mercury is only 46 million kilometers from the Sun (that’s 28.5 million miles for those of you who are resisting assimilation into the metric collective). Compare that to the Earth (and Moon) — we orbit the Sun at an average distance of 149 million kilometers (93 million miles). As you might imagine, being so close to the Sun, Mercury can get pretty darned hot. In full sunlight, temperatures there top out at 426 Celsius (800F). At the poles (where the Sun doesn’t ever shine on Mercury) the temps are -203C (-333F).

I recently read a book called “Higher Than Everest” (available from Cambridge University Press and Amazon). In it, the author describes an “extreme expedition” to Mercury to do some cliff hiking — and he makes it sound like an entirely do-able kind of field trip.

Could humans make this kind of journey? Sure, given the right equipment and time to do it right. Before you ever left Earth, however, you’d need to get plenty prepared. Along with physical conditioning, you’d study maps of the planet, getting to know the cratered surface from old Mariner 10 images. Then, you’d need to get there, using a heavily-shielded spacecraft. After that, you’d need something to get you to the surface safely, and of course a protective suit to keep you cool and safe from the radiation environment once you stepped outside. The good news is that since Mercury’s gravitational pull is much less than Earth’s, you’d weigh a lot less than you would on Earth, even with the survival suit. The hike itself would be about like walking across rough terrain on Earth — lots of rocks and boulder fields. Climbing would be a bit more difficult just due to your bulky space suit. And, you’d need to be a lot more careful than you ever would on an Earth hike. But it could be quite the adventure!

Wanna look for Mercury this year? Your best bets in 2002 are to look to the western horizon immediately after sunset (never look directly at the Sun!) around May 4 and September 1st. If you’re an early riser, look along the eastern horizon immediately before sunrise during around June 21st and October 13th this year. It won’t be an easy sight to see, but it’s worth trying. Just remember to be careful and protect your eyes!

The Solar System

This is the solar system in which you live — minus the Sun, Pluto, and a boatload of ring particles, asteroids, moons, and comets. All these planets have been visited by spacecraft missions sent from Earth sometime in the last 40 years. Why do we routinely fling probes out to these worlds when it would be far more fun to simply visit them? Well, for starters, visiting other planets — even our own Moon — isn’t a simple proposition. I wish it were — science fiction stories make it seem easy, but they don’t always dwell in the millions of details that would accompany each crew into space. Sending people to space is a tough thing to do but eventually we’ll be out there walking the dusty plains of Mars and scooting above the rings of Saturn.

Humans have the invaluable eye of experience and judgment, which all explorers use to analyze their surroundings and figure out how things got to be the way they are. It’s one thing to look at a canyon in photographs taken by an orbiting spacecraft, but quite another to drive into that canyon, hike its walls, and analyze soil samples for some understanding of its chemical and geological evolution. We can send machines to do the grunt work, but they can’t do the analysis that a well-trained scientist can do in a single glance.

But, people need special environmental suits and spacecraft to protect them from the hostile environment of interplanetary space and the conditions at other planets. There’s no way right now, for example, that we can send anybody to the surface of Venus. We simply don’t have the technology put together to shelter people from the high temperatures and pressures that exist at the Venerian surface. Actually, right now we don’t even have an interplanetary spacecraft that can get them to the other planets. It’s far easier to send packages of specially-hardened electronics that can stand up to the punishing rigors of planetary exploration. It’s one thing to fry a spacecraft in the high radiation environment at Jupiter, for example, but obviously a far different proposition risk turning human explorers into crispy critters.

For now, however, we have to work with images and data sent back from our flotilla of planetary missions. We still learn a lot, and in a way, we’ll be better prepared for the time when our children and grandchildren are out there with pickaxes and soil sample kits doing the kinds of hands-on geology field trips that we can only dream of today.

I read in the paper the other day about a newborn baby girl in Afghanistan and how her mother’s hopes for her future were looking a bit brighter now than in past years. I kinda wonder about her too — what will she grow up to be? Maybe she’ll become an astronomer and learn more about the world that is her namesake, or study to be a doctor, or raise a family in freedom, or be a political leader in her country.

This little Afghani Venus is named after the second planet from the Sun, an avatar revered in mythology as the goddess of love. What a lovely name for a tiny new life!

Yet, the planet itself makes the drought-ravaged lands of Afghanistan where baby Venus now lives look like a veritable garden of Eden. This distant world is veiled in noxious clouds, which hide a hot, poisonous, volcanic landscape where no human being could possibly live — let alone fall in love!

Venus in the glow of sunset, imaged by the astronauts onboard the shuttle Atlantis

Starting in early March, the planet Venus will make its own 2002 debut, in the evening skies just after sunset. If you have a clear view of the sky check it out after sundown — it should be a bright, beautiful, almost-but-not-quite starlike object hanging there in the deepening western twilight. Watch it night after night throughout the spring and summer. On the night of May 7 it will appear in close conjunction with the planet Saturn, and with Mars on May 10. It dances around with Jupiter on the evening of June 3.

None of these conjunctions are particularly mysterious or have any cosmic significance. They happen because as planets move around the Sun in their orbits sometimes they appear in the same part of the sky as seen from Earth. They aren’t close to each other, really, nor are they exerting some magical influence because of where they happen to appear. If you see five people standing out in a field and you move so that two of them are in line with each other it doesn’t mean that they are somehow cosmically aligned. Same with the planets.

If you want more information on where to look for Venus or any other night-sky sight from your location, point your browser to the Sky & Telescope web site. There’s an interactive JAVA star chartmaker that allows you to input your location — and will compute a chart for your viewing site. Give it a whirl!

Binoculars.

That’s the answer to one of the first questions people ask about astronomy: “What do I need to look at the night sky?” This is, of course, assuming that they already know they can simply walk outside and look up at a starry evening. Don’t laugh. You’d be surprised at the ideas people hold about the sky. Planetarium people get lots of questions from the public about how to do astronomy. So do professors of astronomy at universities. Sometimes they’re good questions, sometimes they’re not.

But, I digress.

Here’s the way it works. You get a yen to look at things in the night sky. Maybe you saw a killer pic of some galaxy or planet in the newspaper or at the planetarium. You want to see it for yourself. So, you head outside, look up, and wonder to yourself, “Well, maybe if I had a kick-butt telescope system, I’d be able to see more stuff.”

Wrong. Well, sort of. Sure, you could see more with a telescope — but do you know where to point it? Do you know if that killer object you saw on the HST website is even visible from where you live? And, how would you go about finding it among all those stars?

There’s a little-appreciated fact of life about astronomy that eludes the instant gratification crowd. And, that fact is this: first you go out and look up. Then you decide you want to learn more about the night sky. You’re never going to see the sky as those pictures in the paper and magazines and TV shows make it look.

Never.

It’s true. So, if all you’re after is looking at killer pics of distant space oddities, then there is a wealth of web sites, books, DVDs, CD-ROMs and other media that collect great pics for your browsing pleasure. Go for it. That’s what they’re there for. And doing astronomy that way is one way to explore the universe.

Still… observing the sky doesn’t have a lot to do with those pictures. Observing the sky, at least in the beginning, is all about looking at the whole sky each night, and pushing the limits of your vision to find out how much YOU can see. And what you can learn about what you can see.

The first thing you learn is that you don’t know very much — but that you sure do like looking at those twinkling points of light up there. They sort of call your name. They lie in patterns that catch your eye. If you look long enough, you start to notice other things up there — faint fuzzy blots of light. Could be star clusters. Could be nebulae. You’re not sure.

That’s when those telescope ads start calling your name. However, resistance to them is NOT futile. You will not be assimilated like a drone into the ranks of the “gotta have a telescope” grunts until YOU have learned the sky. You know why? Because once you get a telescope, you’ve limited your field of view. You’ve narrowed it down and put a piece of equipment between you and the sky. You’re allowing IT to define your view. There’s a time and a place for that. Don’t get me wrong — because I have three telescopes. But I also have two eyes that give me a pretty wide look at the sky. So, even though I stumble over three telescopes in the dark, it is equally true that some nights I go out observing without them.

When I want to magnify my vision — I reach for the binoculars and focus in on whatever it is that has caught my attention. Sometimes I just simply sweep the sky with the binos, peering through them to see what will catch my fancy. And then, if I see something through them that is still too faint and fuzzy, I reach for the telescope.

It’s my secret to enjoying the sky. Start with your eyes. And hang a pair of binos around your neck — they’ll come in handy more than you ever expected.

What to do when the weather isn’t cooperating with your desire to do astronomy? That’s the question of the ages. Last night, for example, I was all ready to observe the occultation of Saturn by the Moon. We had lots of breaks in the clouds (often called sucker holes) up to 30 minutes or so before the main event (which occurred at 7:32 p.m. at my location). Then, the rain clouds moved in, and by occultation time it was starting to sprinkle. The heavy rains soon followed. Well, we needed the rain…

What did I do? Since I’m in the middle of writing a new book about astronomy (plus a planetarium script about HST science) I came back in here and worked on the computer for a while. The European Southern Observatory site has some wonderful pictures and results from their many telescope installations in Chile. I noodled around there for a while, enjoying the views across the light-years and downloading some interesting additions to the chapter on galaxies.

If you’re clouded out from observing, it’s probably easiest to plop yourself in front of the ol’ Boob Toob and watch whatever plays across the screen. Sometimes I do that, if I’m not feeling particularly motivated and don’t want to work on my projects any more. But, with the Olympics on, I either watch those, or I can eschew the Plasma Goddess completely for some good reading. Lately I’ve been ploughing through some books for review, and of course I always have a science fiction mag or two to read.

Occasionally I fire up some astronomy software and explore the sky that way. I can always say that I’m learning about tomorrow’s sky — provided it clears up!