Microbes in the Atacama Desert May Hint at Life on Mars
Following rainstorms in the historically arid Atacama Desert in South America, revitalized microbes may show how life on Mars could have survived.
The debate as to whether or not there is life on Mars is essentially endless. We may see the odd flicker of potential from our warm and cozy planet, but the inhospitable temperatures and absence of visible water make it difficult to imagine how anything could have survived over the millennia. A new discovery in the Atacama Desert, however, may show one possible way life may have survived on Mars.
The Atacama Deserted in Chile, is the driest nopolar desert in the world. Located at a high elevation near the Andes mountain range, the Atacama is considered the oldest desert in the world. There are signs of hyperaridity going back 3 million years in certain areas, and there is geologic evidence that some sections of the Atacama haven’t received significant precipitation in over 200 million years.
The area is so dry that many of the mountains – some of which are over 20,000 feet high – are completely free of snow and glaciers. On average, the Atacama typically receives between 0.6 to 0.12 inches of precipitation per year, and some weather stations have never seen rain.
One particular region of the Atacama found at around 10,000 feet elevation is so arid the soil has been compared to Mars – enough so that NASA uses the area as a testbed for experiments related to the planet. But now, rather than just acting as a stand-in for the surface of Mars, the Atacama Desert my hold the key to understanding the Red Planet.
The Atacama Desert recently experienced a rare rainstorm that kickstarted the region’s ecosystem. In 2015, researchers took samples from six locations scattered around the Atacama following the rain and reported that previously dormant microbes that evolved to survive in the harsh environment were flourishing. The researchers then returned in 2016 and again in 2017, and found that without any additional liquid, the microbes were returning to a dormant state. The same could be true on Mars.
“In the past, researchers have found dying organisms near the surface and remnants of DNA, but this is really the first time that anyone has been able to identify a persistent form of life living in the soil of the Atacama,” said planetary scientist Dr. Dirk Schulze-Makuch.
“We believe these microbial communities can lay dormant for hundreds or even thousands of years in conditions very similar to what you would find on a planet like Mars and then come back to life when it rains.”
Although Mars is now completely arid, billions of years ago the planet featured oceans and lakes. And where there is water, there is the potential for life. As the planet cooled and the water disappeared, so too did any traces of anything living, even microbes.
While there probably won’t be rains anytime soon on Mars, the findings in the Atacama suggest that there could be dormant microbes on the planet that have the ability to flourish once again if exposed to water. That gives NASA and planetary scientists another reason to send humans to Mars.
NASA currently has two operational rovers on Mars – Opportunity and Curiosity – and they will be joined in 2021 by a European rover known as the ExoMars. That mission will drill two meters into the soil to look for any signs of life. In other words, don’t expect the debate about life on Mars to go away anytime soon.