Rover will be launched in 2020 to explore an ancient lake. There, an abundant mineral can keep records of life in the Martian past.
By A.J. Oliveira
Nov 15, 2019, 6:51 pm – Posted on Nov 15, 2019, 6:42 pm
None of the many NASA rovers that have ever drifted across the Martian surface could find anything much sought after by scientists: direct traces of organisms that lived there billions of years ago when the planet was habitable. The lack of evidence so far is not necessarily an indication of no life on Mars – the jeeps may just not have searched the right places. But very soon this may change.
The agency's next robotic wheeled mission to explore the red planet will focus exclusively on astrobiology, which is precisely the study of life in the universe. The Mars 2020 rover will be equipped with instruments specifically designed to analyze and collect samples for signs of living beings from the distant past. Even the place itself to be explored was chosen to enhance the chances of finding something.
The Crater Jezero (see video below) was already one of the most promising places on Mars to look for possible evidence from ancient biology. Before Mars turned to a cold red desert, our neighbor had plenty of water and mild temperatures. Satellites showed that 3.5 billion years ago there was a lake within that 45-kilometer-wide crater, and that a river flowed there. Where there is water, it usually has life. And scientists have found the perfect place to look for it.
In an article published in the prestigious scientific journal Icarus, edited by Brazilian planetary scientist Rosaly Lopes, researchers describe the discovery of large carbonate deposits right where the shores of the lake would be. Here on Earth, this material forms traces of organisms that can last all this time, such as shells, corals and stromatolites – fossil rocks created by microbes in aquatic environments.
The possibility of stromatolites on the shores of the old lake made the place one of the most coveted targets for scientists for Martian exploration, not only because they have the chance to find things like fossils of ancient microorganisms. Also because carbonates are time capsules that have kept records of conditions on Mars for billions of years. They form from the interaction between carbon dioxide and water.
Thus, subtle variations that occurred over time were recorded. Studying them allows us to better understand how Mars ceased to be a habitable planet – and when exactly that happened. "The possibility that 'marginal carbonates' formed in the lake environment was one of the most exciting factors that led us to choose to land in Jezero," said Mars Will team Ken Williford in a statement.
It is possible that the deposit is even older and has nothing to do with that aquatic environment. But scientists are optimistic. "Carbonate chemistry on the former lakeshore is a fantastic recipe for preserving old records of life and climate," said Williford. Other recent research has identified large amounts of silica in the river delta – great place to look for buried microbial fossils.
Curiosity's successor rover is scheduled for launch in July or August 2020 and is due to begin its exciting investigation in February 2021. The mission is scheduled to last at least two years and the team expects exploration of the carbonate and delta reserves to take place. at the end of this period – in 2023, therefore. Mars 2020's main goal is to collect samples that could in future be brought for analysis on Earth.