NASA Says It Has Found Evidence of Ancient Life on Mars in a Discovery Large Enough to be Seen With the Naked Eye

NASA said that it has discovered the existence of ancient microbial life on Mars. Sean Duffy, the new administrator of the agency, said a sample gathered by the Perseverance rover has been identified as the “strongest indication of life” ever detected on Mars.

Michael Tice, a co-author of the study and member of the Mars 2020 science team, told the Washington Post about the groundbreaking find. “The thing I find most exciting about this sample is that it contains features large enough to be seen with the naked eye that could be examined to test for past life. That’s surprisingly rare when you are studying evidence for ancient microscopic life,” he said.

Groundbreaking Discovery

The rover made its discovery while exploring Neretva Vallis, an ancient river valley on Mars. Billions of years ago, this channel carried water into the Jezero Crater — a place scientists believe was once a lake that may have contained the early components needed for life.

The reddish, clay-rich mudstones — the 25th sample collected out of more than 30 since Perseverance began its mission on Mars in 2021 — contained carbon molecules, one of the essential building blocks of life, according to New Scientist.

The rocks were also covered with small greenish spots, named “poppy seeds” and “leopard spots,” enriched with iron phosphate and iron sulfide. On Earth, these minerals are usually released when microorganisms consume organic matter, the Independent reported.

“The sample contains what we believe to be a potential biosignature (a feature with a potentially biological origin,” explained study lead author Joel Hurowitz of Stony Brook University. “Microbes will eat the organic matter and react it with the mud, and the by-product of that reaction is these minerals.”

While the exact origin of the material is still unclear, Hurowitz described the find as “the first compelling signal of organic matter that we’ve had since we landed in Jezero Crater.”

However, scientists warn that this doesn’t prove life once existed on Mars. The features could have formed in other ways, such as through a meteorite impact or from heat exposure.

“That’s part of the reason why we can’t go so far as to say, ‘A-ha, this is proof positive of life,”’ Hurowitz told the Independent. “All we can say is one of the possible explanations is microbial life, but there could be other ways to make this set of features that we see.”

A Lot Still in Mystery

Even so, he added that “the available evidence collected by the rover,” including signs that the rocks don’t appear to have been heated, leans more toward “the possibility of microbial activity.”

To know for sure, scientists will need to bring these Martian rocks back to Earth for closer study.

“These rocks are prime targets in the search for ancient life on Mars,” said Nicolas Dauphas, a University of Chicago professor, in an email. “Only [a] Mars sample return can answer the billion-dollar question: ‘Was there ever life on Mars?'”

Getting the samples home, though, may be just as challenging as discovering them. NASA initially planned to return them by 2030, but budget cuts to the Mars Sample Return Mission have delayed the timeline by another decade.

Until then, researchers may have to depend on Earth-based simulations to continue searching for clues. As Hurowitz noted, this delay is frustrating, but the samples remain a key step in uncovering whether Mars once hosted life.