Perseverance strikes once more with an intriguing — but unresolved — clue within the seek for previous life on Mars.
In an historical river channel, the rover detected advanced natural carbon inside and on rocks, planetary scientist Ashley Murphy and colleagues report June 24 in Science Advances. A kind of detections is the primary of their form to be discovered on a rock the rover hadn’t drilled into. Mixed with earlier information from Perseverance, the discovering provides context to a possible signature of long-ago microbial processes on Mars, says Murphy, of the Planetary Science Institute headquartered in Tucson, Ariz.
Perseverance took these measurements in July 2024, when the six-wheeled robotic discovered organic-rich “leopard spots” on the identical website. These spots sparked extensive curiosity as a result of mineral content material of their rims — iron phosphate — which bore similarities to options on Earth recognized to usually be related to historical microbial life.
The newly described natural carbon detections are from the identical 2024 measurements, however they symbolize a deeper dive utilizing a special instrument on the rover, SHERLOC, to characterize the carbon discovered within the rocks and provides particulars about its texture.
SHERLOC measured 4 targets throughout three rocks at Vibrant Angel, a rock formation within the dried-up river that fed the traditional lake now known as Jezero crater. The measurements revealed that this natural carbon is combined in with each the silicate-dominated sediment and later-forming carbonate and sulfate minerals. This means the organics could have been emplaced at two completely different factors within the rocks’ historical past — because the sediments have been first laid down, and later as fluids moved by and altered the rock. These information, nonetheless, can not reveal the origin of the natural carbon, Murphy says.
Planetary scientist Paul Byrne of Washington College in St. Louis says the natural carbon “could possibly be from meteorites or cosmic mud; abiological processes like hydrothermal reactions; or they could possibly be organic in nature.”
Nonetheless, the detection of natural carbon in Vibrant Angel may have compelling implications within the seek for historical microbial Martians. In 2014, seven years earlier than Perseverance landed in Jezero crater, the Curiosity rover detected organics at Gale crater, greater than 3,500 kilometers away. The placement of the Gale crater organics so removed from Perseverance’s organics may point out that if life ever existed on Mars, it might have been widespread.
To find out whether or not the samples collected by Perseverance are indicators of historical life, they must be analyzed on Earth — the rover doesn’t have the devices wanted to characterize the natural carbon’s construction and establish the clusters of atoms hooked up to it. Perseverance has cached 30 samples for doable return to Earth, together with a rock core dubbed Sapphire Canyon that comprises the natural carbon. However funds cuts and shifting priorities have difficult plans for bringing the Martian samples house.
Any data gleaned from these samples is price pursuing, Byrne says. If laboratory analyses reveal that the molecules fashioned abiotically, that might improve scientists’ understanding of how advanced natural chemistry can operate sans life.
“Or maybe we’ll discover … that these compounds have been produced by alien biology,” he says. “That risk is price bringing these samples again to Earth.”
