A Menagerie of Outspoken Opinions on Science, World Politics, and Geek Culture

Monday, February 28, 2005

The Little War God

Mars has a problem: It’s too small. Weighing in at about a tenth of Earth’s mass and about half our planet’s diameter, Mars simply couldn’t hold onto enough of its atmosphere to stay warm. Had it been the size of, say, Venus, its greater gravity would have kept a tighter hold on its air. That air would have trapped more solar radiation (what we call “The Greenhouse Effect”) and equatorial temperatures would probably remain closer to its present day high (around 60° F) instead of its present-day average (about -70° F). Though it’d still be a cold planet with huge polar caps, there’d be lots of liquid water too. And liquid water + basic elements + stable planetary environment + sunlight = life.

But, alas, that is not the case. Little Mars and its weak gravity allowed the majority of the atmosphere to slip slowly away into space, and over billions of years all that’s left is the thin envelope of carbon dioxide we see today. It’s less than 1 / 100 the thickness of our atmosphere; as far as complex life like plants and animals and people are concerned it might as well not even be there. Exposure to Mars’ surface conditions means a fast, painful, gasping death for Earthlings. And for those who still held visions of Burroughs’s Barsoomian Mars, there is insult to injury as well: Mars isn’t even red. It’s more of a mottled dun color … the really red pictures of Mars you’ve seen are either false-colorized images or artists conceptions. The real-color images of Mars have always been around for people to see, but magazines generally don’t print them because they’re boring:

[photo removed]

However, recent discoveries show huge underground water reserves on Mars. They are largely frozen, but in some places there is sub-surface pack ice the size and volume of the North Sea; Mars has plenty of water, it’s just currently more solid than solvent. It wasn’t always so: In ages past, when Mars’ atmosphere was thicker, water ran freely across the surface. There were almost certainly large salty seas, if not outright oceans. Depending on how long this wet phase of Mars lasted, there might have been life as well. In fact, recent discoveries show that methane – which on Earth is a gaseous byproduct of decomposing organic material and a sure sign that life is present – exists close to the Martian surface in some areas. And it’s being continuously replenished somehow.

A Frozen, Buried Martian Sea (ESA Photo) Posted by Hello

No one is saying – yet – that this methane seepage around Mars’ icy areas is caused by living things; we can’t be sure what’s causing it. There could be some weird Martian chemical process taking place, or Mars might for some reason have vast underground reservoirs of methane. We either need to send a very advanced rover, or, far better, some people. They need to dig around in that cold Martian soil, scrape up some of that ancient ice, and test it for hardy little Martian critters that might have adapted to life on a cold, dry, thin-aired world. Life on Earth has itself adapted to some rather extreme conditions, so there is no reason to assume that simple Martian organisms could not have evolved strategies to cope with the drying of the planet and the rarifying of its atmosphere. Mars was wet for a significant part of its history. The water is still there, albeit frozen solid and buried. It would not surprise me – though it’d certainly thrill me to no end – if 10 or 20 years down the road we find the Martian equivalent of bacteria or algae.

Just another small step towards an understanding of our place in the universe, but a giant leap away from the juvinile mythology of a human-centered one. There are those who believe our species is not ready to accept such a thing. I think they are wrong, but that knowledge will come regardless; one day soon we will have to come to grips with the fact that it's not all about us. Better sooner, in my opinion, than later.

I’ve been working on the latest BPCP update, which is huge. I’m two dozen new entries into it and I think I might have just passed the halfway point, so it’ll take another couple lunch hours to finish up. I’ll have it posted before the end of the week though. Maybe even tomorrow or Wednesday.

Have a good week, dear readers.