Did NASA's Perseverance rover find signs of life on Mars? Here's what we know

• The rover’s science instruments found that the formation’s sedimentary rocks are composed of clay and silt, which, on Earth, are excellent preservers of past microbial life.
• The findings were made possible by NASA's Perseverance rover, one of NASA's two car-sized robots exploring the Martian surface for signs that the planet was once habitable.
• Duffy said NASA is examining various ways for potential sample retrieval, including sending humans to retrieve the samples in the 2030s when the first spacefarers could reach the planet.

Has NASA's Perseverance rover at long last found evidence that life did indeed once exist on Mars?

Well, after more than four years of scouring the Red Planet's rocky surface, the intrepid rover has finally given scientists the glimmer of hope for which they'd long been searching.

A sample Perseverance collected in 2024 from an ancient dry riverbed in the Jezero Crater could preserve evidence of ancient microbial life, NASA announced at a news conference Wednesday, Sept. 10. The reddish rock formed billions of years ago from sediment on the bottom of a lake in Jezero Crater, which represents what researchers believes is one of the best places to find evidence that Earth's planetary neigbhor was ever home to life.

The discovery represents "the closest we have ever come to discovering life on Mars," NASA Acting Administrator Sean Duffy said in a statement announcing the find.

"The identification of a potential biosignature on the Red Planet is a groundbreaking discovery, and one that will advance our understanding of Mars,” Duffy continued.

Here's everything to know about NASA's landmark discovery on Mars.

NASA finds 'clearest sign of life' on Mars

The rock, which Duffy said at a news conference Sept. 10 houses the "clearest sign of life" ever found on Mars, was one of 27 rock cores the rover has collected since it arrived at the Red Planet. The sample, dubbed “Sapphire Canyon," was taken from a rock colled in 2024 named “Cheyava Falls."

The rover’s science instruments found that the formation’s sedimentary rocks are composed of clay and silt, which, on Earth, are excellent preservers of past microbial life. They also are rich in organic carbon, sulfur, phosphorous and oxidized iron, or rust.

In announcing the discovery, NASA also released an image of the rock – a fine-grained, rusty-red mudstone.

What is a biosignature?

A potential biosignature is a substance or structure that shows evidence of possible past or present life on a planet. However, biosignatures require further data and study before researchers can confirm a biological origin, according to NASA.

Biosignatures are also distinct from fossilized life, which researchers stressed is not what was found on Mars. Rather, the biosignature was detected in rock that formed at a time when Jezero Crater was believed to have been a watery environment, between 3.2 and 3.8 billion years ago.

What is the Perseverance rover?

The findings were made possible by NASA's Perseverance rover, one of NASA's two car-sized robots exploring the Martian surface for signs that the planet was once habitable.

The rovers are managed from NASA’s Jet Propulsion Laboratory in Southern California.

Scientists believe the geology of Mars may hold valuable clues about past ancient life, and so the robotic vehicles, controlled remotely from Earth, have slowly navigated the rocky terrain to scoop up and collect intriguing samples.

When did the Perseverance rover launch, reach Mars?

Perseverance launched in 2020 from the Cape Canaveral Air Force Station in Florida on an Atlas V rocket, manufactured by the United Launch Alliance.

After a 200-day, 300-million-mile journey to reach Mars, the rover landed in February 2021 in the Jezero Crater and has since spet nearly four years searching for and collecting more than two dozen rock samples – many of which are stored at the first-ever depot on another planet for future retrieval.

Why did Perseverance land in the Jezero Crater?

The bottom of the Jezero Crater – believed to have formed 3.9 billion years ago from a massive impact – is considered to be among the most promising areas on Mars to search for evidence of ancient life. Perseverance's adventures have revealed some insights about the enigmatic Martian geology.

Then in 2024, after years in the trenches of Jezero, Perseverance in December finally summitted the steep Martian crater to begin the next leg of its journey exploring the crater's rim.

NASA's Curiosity rover has also been exploring the Martian surface since 2012 in the Gale Crater.

What is Cheyava Falls?

Perseverance came upon Cheyava Falls in July 2024 while exploring the “Bright Angel” formation. The set of rocky outcrops are located on the northern and southern edges of Neretva Vallis, an ancient river valley measuring a quarter-mile wide carved by water rushing into Jezero Crater.

How did scientists confirm the biosignature?

Analayzing data on an arrowhead-shaped rock from Perseverance's instruments, scientists found a pattern of minerals the team referred to as "leopard spots" that carried the signature of two iron-rich minerals: vivianite, which is frequently found on Earth in sediments, peat bog and around decaying organic matter; and greigite, which certain forms of microbial life on Earth can produce.

Together, the minerals could be evidence of a potential fingerprint for past microbial life on the Red Planet.

Ancient life on Mars may not have been so ancient

What made the discovery particularly surprising was that it involved some of the youngest sedimentary rocks the mission has investigated. That upends a previous hypothesis that the best clues to past life on Mars could be contained in older rock formations.

Put more simply, Mars could have been habitable much more recently than scientists previously thought.

“This finding is the direct result of NASA’s effort to strategically plan, develop, and execute a mission able to deliver exactly this type of science," Nicky Fox, associate administrator at NASA's Science Mission Directorate in Washington, said in a statement.

The peer-reviewed paper detailing the findings was published Wednesday, Sept. 10 in the journal Nature.

What's next for Martian rocks?

The rocks Perseverance has spent years collecting are of high interest to NASA and the European Space Agency, which hopes to one day soon retrieve the samples and bring them back to Earth before humans themselves venture to the Red Planet.

But under President Donald Trump's current budget proposal, NASA's existing Mars Sample Return mission would be canceled.

Duffy said NASA is examining various ways for potential sample retrieval, including sending humans to retrieve the samples in the 2030s when the first spacefarers could reach the planet.

Contributing: Reuters