Perseverance, NASA’s Mars rover, has found evidence of organic chemicals, life’s building blocks, on the planet. The team behind the rover announced the discovery on Wednesday. It’s not quite the proof of life that many have been hoping for, but it’s definitely an intriguing find.

Perseverance discovered the carbon-containing organic chemicals in rocks on the surface of the Red Planet. It found the chemicals in the rocks near the Jezero Crater. The rover did a preliminary analysis of the rocks and discovered the compounds that they contain. However, Perseverance is also sending a sample back to Earth. There, scientists will perform a deeper analysis of the origin of the organic chemicals.