Mars is not the dry, desiccated corpse of a planet we thought it was. In just the last few months, our whole understanding of the Red Planet has changed. There’s water! Liquid water!!! On the surface!!! Seriously, why isn’t everybody freaking out about this?
So if Mars isn’t the absolute desert world we thought it was, then what is it? A lot depends on further investigation of recurring slope lineae (or RSLs). Does RSL water seep up from subterranean reservoirs, or is it sucked out of the atmosphere by chemicals in the surface sands?
Right now, scientists are understandably circumspect when talking about Mars. Too much remains unknown. Too many things that we thought we understood we no longer understand. But I’m not a scientist. I’m a science fiction writer. So let’s now take an imaginative tour of one possible version of Mars.
MARS: A SUBTERRANEAN WATER WORLD
Ancient Mars possessed a dense atmosphere of carbon dioxide and vast oceans of liquid water. This environment supported a fledgling ecosystem of anaerobic bacteria, much like that found on ancient Earth.
But unlike Earth, Mars lost its protective magnetic field, most likely due to the natural cooling of the planet’s interior. As the magnetic field collapsed, the solar wind began ravaging the planet’s surface, stripping away most of that CO2 and water.
And yet, not all was lost. Enough of Mars’s water was trapped underground, shielded from the solar wind, that life still had a chance to survive. The environment would be forever cold and dark, but not so inhospitable that life couldn’t evolve and adapt.
Lingering geothermal heat could provide the Martian survivors the energy they needed to keep going, or perhaps they generated their own energy through chemical reactions using perchlorate salts (strong oxidizers that are ubiquitous in Martian soil).
Much as oxygen (another strong oxidizing agent) enabled the evolution of complex multicellular life on Earth, perchlorate-based respiration could lead to the development of multicellular Martian organisms. And so today, fungus-like plants with elaborate root systems and earthworm-like animals with a keen instinct for finding water may dwell deep underground, concealed from the view of humanity’s most sophisticated landers and rovers and orbiters.
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Okay, this is all a bit of a stretch. Especially that last paragraph. But as a science fiction writer, I’m allowed to stretch the currently available scientific facts.
However, this entire scenario depends on one big assumption: that RSL water comes from somewhere underground. While that seems to be the prevailing wisdom, there is another compelling possibility. What if the water we’ve observed on the surface of Mars has an atmospheric origin?
Tomorrow, we’ll take an imaginative tour of a rather different kind of Mars, and perhaps we’ll encounter a very different kind of Martian.