Astroboffins reckon evidence of Martian life has probably been destroyed where liquid acid flowed on the Red Planet

Fortunately, it looks like Perseverance rover will start digging in the right place

9 Reg comments Got Tips?

Evidence of ancient microbial life in Martian soil will not be easy to find, and some of it may have been destroyed by the flow of liquid acid, according to research published in Scientific Reports.

The idea of life on Mars has tantalized astronomers for hundreds of years. Although no concrete proof of extraterrestrial life has ever been confirmed on the Red Planet, signs that it may have been capable of supporting microorganisms has been steadily mounting as scientists uncover evidence that it once held water on its surface.

But not all liquids are good for Martian life, explained Alberto Fairén, first author of the paper and a visiting scientist at Cornell University. "When clays are exposed to acidic fluids, the layers collapse and the organic matter can't be preserved. They are destroyed. Our results in this paper explain why searching for organic compounds on Mars is so sorely difficult."

Fairén and his colleagues devised a chemistry experiment to mimic Martian soil conditions. They slipped samples of glycine, an amino acid involved in the production of proteins, into clay minerals. Next, they treated the soil-like mixture with radiation, as well as with acidic and alkaline fluids, to see how it might affect the glycine in a closed chamber pumped with the same concentration of gases found on Mars.

Ultraviolet rays and hydrochloric acid destroyed the glycine, turning it into a lumpy gel. The team reckons the same thing probably occurred on Mars too. Acid may have degraded biosignatures like amino acids, making it difficult for rovers to find. "We know that acidic fluids have flowed on the surface of Mars in the past, altering the clays and its capacity to protect organics," Fairén added.

Perseverance, the latest Martian rover to be deployed from NASA, is currently on its way towards the Red Planet. Launched in July, it is equipped to drill into the Martian surface to collect soil samples to return to Earth. The team suggests avoiding regions that might have been flooded with acid.

"Being successful in the search for life in clays on Mars will depend on the characteristics of the fluids that have been interacting with those clays in the past: our paper shows that alkaline fluids will not hamper the capability of clays to host organics," Fairén told El Reg.

"Perseverance got it right from the beginning: the rover is going to Jezero crater, one of the few spots on Mars where carbonates are abundant. And carbonates are evidence that acidic fluids have not been pervasive since their deposition, because carbonates dissolve readily in acids. So, Jezero is a sweet spot for the search for life on Mars."

Perseverance is expected to reach Mars in February. It's the heaviest trundlebot yet, and hosts a range of instruments including some 23 cameras, multiple types of spectrometers, a laser zapper, and two microphones. ®

SUBSCRIBE TO OUR WEEKLY TECH NEWSLETTER


Keep Reading

Briny liquid may be more common on Mars than once thought, unlikely to support life as we know it

Jeez, no need to be so salty

NASA to send Perseverance, a new trundle bot, and Ingenuity, the first interplanetary helicopter, to sniff out life on Mars in July

Mars2020 mission will scout for interesting rocks to bring back to Earth

Here's a headline we'll run this century, mark our words: Alien invaders' AI found on Mars searching for signs of life

World will marvel at tiny electronic brain made of sand taught to think

And it's off! NASA launches nuke-powered, laser-shooting, tank Perseverance to Mars to search for signs of life

23 cameras, microphones and a helicopter on the rover to see and hear the Red Planet in living technicolor

NASA's hefty Martian rover will use an AI brain on a robot arm to map out signs of ancient life on Red Planet

The tiny X-ray bullets are only the size of a grain of sand. Pew! Pew! Pew!

Sorry to drone on and on but have you heard of Ingenuity? NASA's camera-copter is ready to head off to Mars

Vid From the belly of Perseverance comes a revolution in Red Planet exploration

Born slippy: NASA Mars rover Perseverance to persevere on Earth a little longer as launch date pushed back again

A delay until 2022 looms as sensor problems on Atlas V add a few more days to schedule

It's a God-awful smell affair.... is there life on Mars? Rocks ruled out as source of mystery methane on Red Planet

(Yes, pedants, we know natural methane is odorless. Don't get in the way of a Bowie headline)

Biting the hand that feeds IT © 1998–2020