Mars, Europa & Titan… Hopes for Life

The old SF Solar System had native alien races on just about every body. A prime example is Edmond Hamilton’s “Captain Future” series which featured human races on most moons and all the planets – we were all related by common descent from interstellar travellers from Deneb.

By 1960 those hopes were largely dashed by advances in spectroscopy and radio telescopes – even the most ‘hospitable’ planet, Mars, seemed bare of anything but scabby lichens.

By 1976 – in the wake of “Viking” – even lichens seemed a long shot.

But Mars didn’t wait for us to go visit to get rock samples. Billennia ago bits of Mars were blasted into space and ever since they’ve rained down as the occasional meteorite. In 1996 the Antarctic discovered meteorite, ALH 84001, became famous because microscopic traces looked like bacteria and its chemistry indicated it would’ve been palatable to life at some point in time past. Since then the argument for, and against, this claim has oscillated back and forth. Now new analysis has revived the ‘for case’…

Fresh claim for fossil life in Mars rock

…so who knows? But not really SF material, chiefly because life is probably common between the two planets anyway, due to the meteorite trading that occurs with every big impact. Mars life, as interesting as it will be, is in all likelihood akin to Earth-life.

Further afield are two more interesting prospects for “life as we don’t know it”, Europa and Titan. Titan is in the news again because of the discovery that acetylene is far more abundant in its methane lakes than anyone first imagined, up to 1% in solution…

Icy moon’s lakes brim with hearty soup for life

…which is great news for acetylene-powered life. But I don’t expect such life to be visible without a microscope either. Or rather individually I don’t expect to see it. However bacterial colonies and their traces can be large and colourful… something for a Titan rover to look out for around the lakes.

“I think the results are very exciting and further support the possibility for life on Titan,” says Dirk Schulze-Makuch of Washington State University in Pullman, one of the scientists who proposed the possibility of acetylene-eating life in 2005. “Titan should be one of the two top targets for future astrobiology missions, the other being Mars.”

Dirk’s webpage is here.

If we want ‘alien fish’ then we need an oxygenated ocean. Europa could have a complex biosphere because it probably has just such an oxygen-rich environment. Richard Greenberg has been studying Europa for some time and believes it provides a huge variety of habitats…

Thin Ice Opens up Opportunities for Life on Europa

…the tidal flexing of the ice shell means a flow towards the surface and away on a daily basis, keeping things stirred up and interesting for any life. Europa is also bathed in radiation from Jupiter’s magnetosphere which produces oxidants in its icy shell, which in turn get buried and drawn down into the ocean below…

Europa’s Oxygenated Ocean… Discovery News

…so the situation isn’t so hopeless in our Solar System as it once seemed. There’s enough oxygen to sustain about 3 million tons of sea-life. Doesn’t sound like much, but it’s nothing to sneeze at. There really might be fish – alien, unearthly ones – swimming beneath the crazed ice-shell of Europa.

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