I believe in Martians. The planet Mars was once a wet, warm world like Earth, and it stayed that way for billions of years. That means Mars had ample opportunity to start growing its own organisms, even if things didn’t turn out quite as successfully as they did on Earth.
And while the evidence is not exactly conclusive, there’s plenty of reason to believe that life of some kind did exist and still exists on the Red Planet.
Surviving in Saltwater
On Monday, we looked at Martian water, which some claim is way, way too salty to support life. Meanwhile, here on Earth, scientists have been investigating a creepy, blood-red substance seeping out of Antarctic ice.
Turns out this red substance is produced by large communities of bacteria living beneath the ice. These bacteria have been virtually cut off from the rest of the world for over a million years, surviving in a frigid and super-salty environment almost identical to what hypothetical Martian microbes would have to endure.
Click here to learn more about these Antarctic bacteria.
Debating Over Meteorites
I’m sure we all remember meteorite ALH-84001. That’s the meteorite found in Antarctica that allegedly contained fossilized Martian microbes.
Although the origin of these “fossils” has been called into question, this piece of evidence has not been fully discredited. The scientific debate is ongoing, and additional Martian meteorites have been discovered bearing still more hints of possible biological activity on Mars.
The most recent meteorite, named Tissint, somehow got organic material wedged into cracks and fissures in its surface before traveling to Earth.
Click here for more information about Tissint.
Sniffing Martian Methane
And on the surface of Mars itself, the Curiosity rover has detected several sudden spikes in atmospheric methane, one in late 2013 and another in early 2014. This is mysterious for two reasons: where did all this methane come from, and where did it all go?
Although there are several possible explanations, scientists seem hard-pressed to account for these sudden, dramatic fluctuations of atmospheric methane without involving some sort of native Martian organisms.
Click here for more about methanogenesis on Mars.
Of course, this is all circumstantial evidence. The anomalous methane doesn’t have to come from biological sources, and some experts suspect that the rover itself, which apparently has pressurized methane stored inside it, might simply have sprung a leak. Evidence from Martian meteorites will always be controversial, and discovering bacteria sequestered beneath Antarctic ice is not the same as finding microbes on Mars.
Still, this circumstantial evidence is piling up. It’s enough to convince me that life probably exists on Mars, but what about you? Do you believe in Martians?
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Today’s post is part of Mars month for the 2015 Mission to the Solar System. Click here for more about this series.