Exploring the Solar System: Mars

Mars!
Mars!

Of all the planets in the Solar System, to my mind, this place rocks! Why do I say that? I’ve always wanted to go there, ever since I was a kid and played “Going to Mars” with my sibs and cousins out in a field by our house. I hadn’t even read any of the Edgar Rice Burroughs Mars books at that time, I just knew it had to be an interesting place!

Fictional Mars was peopled with all manner of strange beings — princesses, heroes, alien beings called Thoats, and they all lived a sort of adventurous life among the canyons and jungles of the imaginary surface of the Red Planet.

All those beings began to dissolve into the fictional plane when telescopes got powerful enough to give us a view of Mars that was more like the Arizona desert than the jungles of Africa. When the first spacecraft missions visited the planet beginning in the 1960s, the world of thoats and princesses vanished back to the bookshelves.

Today, we know Mars is a dry and dusty desert planet, with the remains of ancient lakes and streambeds showing that water once existed on the surface, and two polar caps of water and carbon dioxide ice. Like Earth, it has volcanoes — but its calderas have been sleeping for millennia. It has an atmosphere not much thicker than the Earth’s stratosphere, and its air is mostly carbon dioxide — the same waste product we breathe out as we breathe in oxygen. The surface is split by canyons, pockmarked by impact craters, and covered with fine, wind-blown dust and sand.

Think we’ll ever get to explore this planet in person? For more than thirty years, people have made mission plans to take humans to the Red Planet. The “Case for Mars” meetings (which were held beginning in the early 1980s and have been repeated every few years at the University of Colorado) included many sessions on ways to get to Mars, surviving on its surface, and the many scientific studies that explorers could do. Today the Mars Society and others carry on the legacy of planning — with an eventual goal of putting people on the Red Planet sometime in the next decade (or sooner).

So why do I think this seemingly dead planet rocks? Because of all the planets in the Solar System, Mars is the most like Earth — and offers the best chances for actual human exploration and eventual habitation. It fires our imagination and gives us a place to go next. Understanding how this planet came to be the way it is helps us learn more about the evolution of the solar system as a whole, and our own home planet in particular. Besides, it’s just plain darned cool!

Exploring The Solar System: Mercury

Mercury
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!

Exploring Science and the Cosmos

Spam prevention powered by Akismet