A New Study Reveals How Humans Could Accidentally Murder Life on Mars

Be careful what you wish—even if what you’re wishing for is something you really, really need. Take, for example, Chile’s Atacama Desert. Widely considered the driest place in the world, it has an average rainfall of as little as 0.04 inches per year and meaningful rainfall of about 1.5 inches (enough to leave short-lived shallow lagoons) only once per century on average. Even that much water has been hard to come by, with climate records suggesting no significant rain has fallen in the past 500 years. So you’d think it would have been welcome when the desert got two storms, in 2015 and 2017, not to mention a few much smaller rain events in between. The Atacama should—or at least could—have burst to life, with what Cornell University astrobiologist Alberto Fairén called “majestic blooms.” But, according a new paper by Fairén and his colleagues, published in the journal Scientific Reports, what followed was a lot more death than life. That has implications not just on Earth, but on arid planets like Mars. Though the Atacama is indeed an all-but-sterile place, there are some organisms that manage to scratch out an existence there. At least sixteen microbial species are known to populate the deep soils of long-dry lake beds, using nitrates—a salt form of nitric acid—as food. What exceedingly minimal moisture there is comes from the trace rainfalls as well as what’s known as the altiplanic winter, be...
Source: TIME: Science - Category: Science Authors: Tags: Uncategorized atacama desert climate exobiology Mars onetime Rain Source Type: news