Organic molecules discovered within a stone on Mars cannot be fully explained by nonbiological processes, and it's "reasonable to hypothesize" that living things could have formed these odd organic molecules, a NASA-led team reports in a new study. However, this doesn't mean scientists have found definitive proof of life on Mars, they cautioned.
In March 2025, scientists reported the discovery of the largest organic molecules ever found on Mars. These long chains made of hydrogen and carbon may be the fragments of fatty acids, which are often created through biological processes.
