Moon and Mars

Here on Earth, life inhabits just about every nook and cranny you can think of. That includes one of the driest spots on the planet — the Atacama Desert of Chile. Some parts of it receive an average of just a few millimeters of precipitation per year. And they can go many years without a drop. Even so, microbes live just below the desert surface. And that has implications for the possibility of life on Mars.

An international team studied the Atacama in 2015, ’16, and ’17. The scientists dug into the desert in several locations in search of microbes. The first expedition came not long after a rare rainfall. But little or no rain fell after that.

In the wetter 2015 samples, the team found abundant microscopic life not far below the surface. There was less activity the following years, but there was still some, even in the most arid locations. That suggests that some organisms have adapted to living in the Atacama, where it’s not only dry, but other conditions aren’t good for life, either.

Mars is even drier than the Atacama, and the surface chemistry isn’t very hospitable. Yet the Atacama study suggests that if microbes evolved on the young Mars, they might have adapted as the planet dried out. They could still exist today, living below the surface of this desert world.

And Mars is in great view late tonight. It’s just below the Moon as they climb into good view after midnight, and even closer to the Moon at first light.

Script by Damond Benningfield