Underground Lake Discovered on Mars

So, this was really big news a couple weeks ago, and I was going to write about it last week. But then I found the German beer bottle fiasco and thought it was too good to pass up writing about. Hey, that Martian lake's lasted this long, it can wait a couple weeks.

Anyway, we've found a lake. Filled with liquid water. On Mars. It's a mile underneath the southern ice cap, so we won't be visiting it any time soon, but still, liquid water. A significant body of liquid water on Mars, roughly analogous to Lake Vostok in Antarctica. The Red Planet seems to be sending us mixed signals here, on the one hand, we've confirmed that Mars simply doesn't have enough carbon dioxide left to be terraformed, but on the other hand, we've got this. A lake, about 12 miles across and at minimum 3 feet deep. That's a decent amount of water, and considering what we know, if there's liquid water, there's a good chance there's life.

This is still science we're talking about here, and the discovery still needs to be confirmed. But if it is a lake, it seems like it could be an excellent warm-up for when we explore Europa and Enceladus. Mars is much closer, after all, and I think it's likely we'll get there sometime this century. The water isn't that far underneath the surface, and if there is life floating around in this lake, surely that would boost the odds of life existing under the ice of those moons. All we need to do first is get to Mars. No problem, right?

Liquid Water on Mars

It's generally accepted that billions of years ago, Mars was a pretty wet place. But over time, Mars lost its atmosphere and its water, and the oceans that probably existed on the surface dried up. With atmospheric pressure at 1% of Earth's, and with temperatures rarely getting above freezing, liquid water on the surface of Mars today seems like an unlikely prospect. But not impossible. In the past few years, space probes have found features called recurring slope lineae, dark streaks that appear in the Martian summer and fade away during the winter. It was suspected that liquid water was forming these features, but the evidence was not there.

As you may have guessed, today NASA announced that the evidence had been gathered, and they could definitively say that the RSL were in fact formed by liquid water. Now, I don't want to overstate the importance of this discovery. The water is filled with a kind of salt called perchlorate, which lowers the freezing point of the water to well below zero. That's good for liquid water, not good for life, as we know of no organism that could live in such an environment. In addition, we're not talking about some big gushing stream running down a crater, but what basically amounts to damp soil. There's not a lot of water available. However, finding any amount of liquid water is fantastic news. Just because life as we know it could not survive there doesn't mean it's completely inhospitable, and any manned missions to Mars could certainly use it. I think it's absolutely incredible that for so long, we assumed that liquid water could only exist on Earth, but we've found it on Europa, on Enceladus, and now, on Mars. That's 4 different planetary systems that we can find liquid water, spread out across a billion miles of space. At this point, I would be more surprised if life did not exist elsewhere in the Solar System then if it did, because with every discovery of liquid water, the odds of finding life improve.