NASA's Curiosity rover has discovered long-chain organic molecules on Mars that researchers say cannot be explained by non-biological processes alone. The findings, published in the journal _Astrobiology_, suggest these molecules could be remnants of ancient life on the Red Planet, though scientists remain cautious about definitive claims.

Despite millions of years of destructive radiation pummeling the Martian surface, the concentration of these alkanes appears too high to result from known abiotic sources. A team led by NASA Goddard's Alexander Pavlov studied how radiation would have degraded these molecules over 80 million years, concluding the original abundance was likely much higher than previously thought.

The discovery strengthens the case that Mars could have supported life billions of years ago when it had oceans, rivers, and lakes. While researchers acknowledge the possibility of still-unknown non-biological processes, they argue that biological origins remain the leading theory. The team calls for further research into how radiation affects these molecules under Mars-like conditions to better understand their origins.