The ongoing hunt for martian life is looking less bright. New soil analysis of the Red Planet finds it to be experiencing a 600-million-year long "super-drought," painting a portrait of a dry and lifeless surface. Time to refocus our alien-finding efforts elsewhere? Here's what you should know:
How do we know Mars is so dry?
A team from the Imperial College in London spent three years analyzing soil samples collected during NASA's 2008 Phoenix mission. The scientists wanted to find out how long it had been since the minerals made contact with water. "We found that even though there is an abundance of ice, Mars has been experiencing a super-drought that may well have lasted hundreds of millions of years," study lead author Dr. Tom Pike tells The State Column. "We think the Mars we know today contrasts sharply with its earlier history, which had warmer and wetter periods and which may have been more suited to life."
Why is the possibility of life so dismal now?
Well, even though there was once water on the surface, the soil samples suggests it was only there for about 5,000 years, says Alex Knapp at Forbes — a very short timeframe. "That means it's relatively unlikely that life had a chance to evolve." (It took millions of years for multi-cellular life to evolve on Earth.) This study also proves that this dry soil is uniform across the planet, says Nick Collins at Britain's Telegraph; in fact, Mars formed "under similarly arid conditions to the Moon" — another celestial body famously devoid of life.
So is hope of martian life lost for good?
Not entirely. There's still hope — at least underground. "After all, it's clear from the presence of gypsum [a mineral that requires water to form] on Mars that water has flowed there, both on the surface and most likely underground, too," says Knapp. "It's not hard to imagine that there are at least microbes of some sort living on Mars. But I imagine it will be quite a few decades before we find out for certain."