The driest desert on Earth may hold the key to finding life on Mars.
The diverse microbes found in the shallow, clay-rich layers of the arid Atacama desert of Chile suggest that similar sediments below the Martian surface may contain microorganisms, which could easily easily found on future exploration or landing craft missions.
Led by the Cornell University and the Centro de Astrobiología of Spain, the scientists are now introducing a type of planetary primer to identify microbiological markers on shallow excavations in Martian clay, in their work published today (5/11/2020) in Natural Science Report.
In the arid environment of Atacama, the scientists found layers of wet clay about a foot from the surface.
“Clay is inhabited by microorganisms,” said corresponding author Alberto G. Fairén, a visiting scientist at Cornell University’s Department of Astronomy. “Our discovery suggests that something similar could have happened billions of years ago – or it could still happen – on Mars.”
If the bacteria existed on Mars in the past, their biological markers would likely be preserved there, Fairén said. “If bacteria were still present today, the latest life possible on Mars could still be resting there,” he said.
The Red Planet will see gliders on the surface there over the next few years. NASAThe rover’s Perseverance will land on Mars in February 2021; The Rosalind Franklin European probe will arrive in 2023. Both of those missions will look for microbial markers in the clay layers below the planet’s surface.
“This article helps guide our search,” said Fairén, “to inform where we should look and which tools to use to find life.”
In the Yungay region of the Atacama desert, scientists found clay, a previously unreported habitat for microbial life, is home to at least 30 species of phytoplankton. Salt is composed of metabolic bacteria and ancient bacteria (protozoa).
The researchers’ discovery of Atacama reinforces the notion that early Mars may have had a similar bottom surface with protected habitable niches, especially during the first billion years in its history. .
“That’s why clay is so important,” he said. “They preserve organic compounds and biomarkers extremely well and they are plentiful on Mars.”
Reference: “Humid sub-surface humid smectite inhabiting the hyperarid core of the Atacama desert as a analogue for the search for life on Mars” by Armando Azua-Bustos, Alberto G. Fairén, Carlos González Silva , Daniel Carrizo, Miguel Ángel Fernández-Martínez, Cristián Arenas-Fajardo, Maite Fernández-Sampedro, Carolina Gil-Lozano, Laura Sánchez-García, Carmen Ascaso, Jacek Wierzchos and Elizabeth B. Rampe, 5 November 2020, Scientific reports.
DOI: 10.1038 / s41598-020-76302-z
The lead author of the paper is Armando Azua-Bustos, a researcher in Fairén’s group at Centro de Astrobiología, Madrid.
The research is funded by the European Research Council.