Mars breakthrough as major discovery could prove there was life on Red Planet

The large compounds provides evidence that organic chemistry on the plane was more advanced (Image: NASA Goddard via YouTube)

A major discovery of the largest organic molecules ever found on Mars has been made. The carbon chains could be an example of life on the Red Planet. The molecules point to a more complicated past on the planet, suggesting that prebiotic chemistry may have advanced further on Mars than previously perceived. 

It was NASA's Curiosity rover's Sample Analysis at Mars (SAM) mini-lab that helped make the discovery. SAM is cofunded by the French space agency CNES and part of NASA's Curiosity rover, which has been exploring Gale Crater since 2012. Now scientists from CNRS (the French National Centre for Scientific Research) are intrigued by what this could mean for the Red Planet.

Scientists examined the Cumberland rock sample, that features chemical information dating back 3.7 billion years, and found compounds made up of 10,11, and 12 carbons, thought to parts of fatty acids preserved in the sample. Fatty acids are organic molecules that on Earth are "building blocks of life".

Living things produce fatty acids to aid the formation of cell membrances as well as perform a number of other functions. However, they can also be produced without life, for example through chemicaly reactions trigged by different geological processes.

There is currently no means of confirming how the molecules came about. However, the discovery does act as a major breakthrough for scientists. The findings were published in the Proceedings of the National Academy of Sciences journal on March 24, 2025.

Caroline Freissient, the lead study author and research scientist at CNRS said: "Our study proves that, even today, by analysing Mars samples we could detect chemical signatures of past life, if it ever existed on Mars."

Smaller organic molecules have been discovered on Mars before. Caroline Freissent co-led a team that found organic molecules in the same sample which was drilled in 2013. However, the large compounds offer the first evidence that organic chemistry advanced towards the kind of complex level that is required for an origin of life on Mars.

Additionally, it adds to the possibility that "biogsignatures" - large organic molecules can only be formed in the presence of life, can be preseved on Mars, putting to rest the concerns that such compounds get destroyed after tens of millions of years of exposure to severe radiation and oxidation.

Scientists say that the findings bodes well for plans to bring samples from the Red Planet to Earth, in order to analyse them with the most sophisticated instruments available here.