Spanish lagoon proposed as Mars ‘astrobiological time-analog’

The continued seek for indicators of life on Mars depends partly on terrestrial analogs—locations on Earth carefully resembling the previous or present geology and local weather of the pink planet that may be readily explored.

A brand new research proposes to deal with one other technique: “time-resolved analogs,” that are dynamic analogous Earth environments the place modifications might be analyzed over a few years. Alberto G. Fairén, a visiting scientist within the Division of Astronomy, within the Faculty of Arts and Sciences, has led this inaugural research in his native Spain.

Fairén is co-lead creator of “Ecological Successions All through the Desiccation of the Hypersaline Tirez Lagoon (Spain) as an Astrobiological Time-Analog for the Moist-to-Dry Transition on Early Mars,” which printed Feb. 8 within the Nature journal Scientific Reviews. The opposite co-lead creator is Jose L. Sanz of the Autonomous College of Madrid (UAM).

Their investigation has been performed within the extraordinarily salty Tirez lagoon in central Spain, which had skilled alternating dry and moist intervals over the course of twenty years, earlier than reaching total desiccation in 2015.

Their key findings: If life existed on Mars when the planet had liquid water on its floor, its desiccation wouldn’t have essentially implied that life disappeared for good. As well as, lipids—resembling fatty acids or their derivatives—have a better resistance to degradation and ought to be most well-liked targets within the seek for life in a waterless world.

Fairén, a member of the Cornell Heart for Astrophysics and Planetary Science and a analysis professor on the Heart of Astrobiology (CAB) in Madrid, started research of Mars analogs whereas pursuing his Ph.D. at UAM.

“On the time,” Fairén mentioned, “my adviser’s crew was already occupied with Tirez, principally as an analog of Jupiter’s moon Europa, due to the excessive focus of salts within the Tirez waters.”

They’ve since turned their consideration to Mars, notably places that contained water ponds earlier than drying up in the course of the Noachian (round 4 billion years in the past) and Hesperian (3.7 to three billion years in the past) intervals. Fairén’s analysis group—which included scientists from CAB and UAM—carefully monitored Tirez’s gradual desiccation over 25 years, utilizing it as a possibility to higher perceive the evolution of microbial communities in small, dried-out lagoons.

Samples from Tirez have been collected and analyzed in 2002, in the course of the early phases of desiccation, and once more in 2021, when the lagoon was fully dry.

“We conclude that any attainable early ecosystems on Mars in all probability collapsed when liquid water disappeared,” Fairén mentioned, “however the altering atmosphere would have triggered world ecological successions, with hypothetical microorganisms evolving methods just like these of microorganisms residing in Tirez now, tailored to thrive at very low water exercise within the desiccated sediments.”

The group will proceed to watch Tirez, Fairén mentioned, noting that any modifications in its standing concerning water content could be of eager curiosity.

“It might be notably attention-grabbing if the continuing dry decade in central Spain would expertise some alleviation and we may witness no less than a partial comeback of the water desk,” he mentioned. “That might permit us to increase much more our idea of the astrobiological time-analog for Mars, as a result of the desiccation of Mars was a stepwise course of.”

“Analyzing the response of the microbiota in Tirez to the presence of liquid water once more, after years of full desiccation, would offer new insights to grasp the evolution of attainable historic ecosystems on Mars,” he mentioned.