Tuesday, May 17, 2022

Scientists find evidence of water in Mars rock, but no signs of life


Swedish scientists analyzed this Martian meteorite that was found on Earth and concluded that it had only very limited interaction with liquid water.
 Photo courtesy Josefin Martell/Lund University/UPI

May 16 (UPI) -- Swedish scientists say a study of a meteorite from Mars indicates that it had only very limited exposure to liquid water -- an indication that it's unlikely life was present on the Red Planet in recent times.

Scientists at Lund University in Sweden agree that widespread presence of water would have been a prerequisite for life on Mars, but advanced scans of a 1.3-billion-year-old Martian meteorite revealed only trace contact with hydrogen, the key element in water.

The results of their study were published last week in the academic journal Science Advances.

While samples of Martian rocks are being collected by NASA's Perseverance rover and are expected to be available by 2030, scientists got a jump on the process with a Martian "Nakhlite" meteorite -- rock ejected from the Red Planet by a meteorite impact hundreds of millions of years ago.

The chunk is known as the Miller Range 03346 nakhlite, a 1.6-pound rock that scientists discovered in Antarctica's Miller Range in 2003.

Josefin Martell, geology doctoral student at Lund University, said the goal of studying the meteorite was answering whether there was ever a "major hydrothermal system" on Mars.


NASA's Perseverance Mars rover is seen on the surface of the Red Planet on February 24. The rover, among other things, is collecting rock samples from the surface for analysis. 
File Photo by NASA/UPI

"Since water is central to the question of whether life ever existed on Mars, we wanted to investigate how much of the meteorite reacted with water when it was still part of the Mars bedrock," Martell said in a statement.

Researchers used neutron and X-ray tomography to study meteorite -- neutron tomography was used because neutrons are very sensitive to hydrogen -- and found that only a fairly small part of it seems to have reacted with liquid water.

Thus, they reasoned, it probably wasn't a large hydrothermal system that produced the reaction, but rather "small accumulations of underground ice" that melted when the meteorite impacted the planet about 630 million years ago.

Scientists said the findings "have direct implications for the habitability of the Martian subsurface in the Nakhlite source region, where any habitable environments were localized and very short-lived, reducing the chance of life's emergence or survival on Mars" during its most recent historical period.

"Of course, that doesn't mean that life couldn't have existed in other places on Mars, or that there couldn't have been life at other times," Martell noted.

Dispatches from Mars: Perseverance rover sends images

NASA's Perseverance Mars rover, using its Mastcam-Z camera system, captured this view of the Martian sunset on November 9, 2021, the 257th Martian day, or sol, of the mission. Martian sunsets typically stand out for their distinctive blue color as fine dust in the atmosphere permits blue light to penetrate the atmosphere more efficiently than colors with longer wavelengths. But this sunset looks different: Less dust in the atmosphere resulted in a more muted color than average. The color has been calibrated and white-balanced to remove camera artifacts. Photo courtesy of NASA | License Photo

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