NASA’s Mars rover has found new clues pointing to past life on Mars

Scientists may be one step closer to searching for signs of past life on Mars after the latest discovery by the Curiosity rover.

About a year ago, a car-sized robot — one of two NASA rovers orbiting the Red Planet — found an interesting rock sample that had some interesting features. In the rocks, Curiosity’s instruments detected organic compounds that are often produced by living things on Earth.

Although geological processes may also make the material present, researchers concluded in a study published on February 4 in the journal Astrobiology that such non-biological processes may not be the only factor. The discovery opens the door to the possibility that Mars once had life, though scientists have stopped short of making that claim definitively.

Here’s everything to know about Curiosity and the latest discoveries made by its observations.

What is NASA’s Curiosity Rover?

NASA’s Curiosity rover, along with Perseverance, is one of the agency’s two car-sized robots exploring the Martian surface for signs that the planet was once habitable.

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

The Curiosity rover began its journey to Mars in November 2011, landing in August 2012 in Gale Crater, the border between Mars’ cratered southern highlands and its smooth, northern plains. While exploring the crater, believed to have formed 3.7 billion years ago, Curiosity collected 42 powdered rock samples with a drill on the side of its robotic arm.

The Mars rover has discovered organic matter known as fatty acids

In March 2025, scientists reported identifying trace amounts of three different organic materials – decane, undecane and dodecane – in a rock sample analyzed using Curiosity’s onboard scientific instruments.

The largest organic compounds found on Mars, according to NASA, were believed to be fragments of fatty acids preserved in the ancient mudstones of Gale Crater. On Earth, fatty acids are key indicators of life, produced mostly by living organisms.

Living organisms could form molecules in Martian rocks

Because Curiosity’s observations alone did not lead scientists to conclude that the molecules were made by living things, the researchers conducted their own follow-up studies.

The main question on their minds was whether any non-biological sources – such as meteorites hitting the surface of Mars – could be responsible for the existence of fatty acids.

To answer the mystery, scientists conducted radiation experiments and mathematical modeling to effectively turn back time—80 million years to be exact. How long had it been since rock samples containing organic compounds appeared on Mars, and how long would any organic matter have been present before being destroyed by cosmic radiation?

In the study, the team determined that non-biological sources actually “cannot fully explain the abundance of organic compounds,” NASA said in a February blog post announcing the findings. For that reason, they concluded that living organisms may have formed fatty acids.

But they stopped short of saying it was conclusive evidence that Mars once had life, and said more studies are needed to understand the process by which organic molecules break down on the planet.

Eric Lagatta is a Space Connect reporter for the USA TODAY Network. Reach him at elagatta@usatodayco.com

This article originally appeared on USA TODAY: NASA’s Curiosity rover helps find possible signs of life on Mars