NASA Curiosity rover finds mysterious life linked molecules on Mars

NASA's Curiosity rover has found many organic molecules on Mars. These include compounds that scientists believe are key for life to begin. Some of these molecules might be billions of years old. They were preserved in old, clay-rich rocks that once held water.

One exciting discovery is a molecule that looks like a building block of DNA. This raises questions about Mars' past. While not proof of life, it suggests Mars might have been more likely to support life than once thought.

New Experiment Uncovers Ancient Chemistry

This discovery comes from a new chemical experiment done on another planet for the first time. The results show that the Martian surface can keep molecules that could be signs of ancient life. However, the experiment cannot tell if these compounds came from past life, natural geology, or meteorites.

To prove past life, scientists would need to bring Martian rock samples back to Earth for detailed study.

Amy Williams, a geological sciences professor at the University of Florida, led the research. She is part of both the Curiosity and Perseverance rover teams. Curiosity landed on Mars in 2012 to see if the planet once had conditions for tiny life forms. Perseverance, which landed in 2021, is looking for direct signs of ancient life.

Williams helped create the experiment. She noted that they believe they are seeing organic matter preserved on Mars for 3.5 billion years. This evidence shows that ancient organic matter can be preserved. This is important for understanding if an environment could support life. It also shows that searching for signs of life in preserved organic carbon is possible.

Williams and an international team published their findings in Nature Communications on April 21.

DNA-Like Molecule Among Discoveries

The experiment found over 20 different chemicals. One was a nitrogen-containing molecule similar to those that build DNA. This has never been seen on Mars before. The rover also found benzothiophene, a large sulfur-containing molecule with two connected rings. Meteorites often bring this molecule to planets.

Williams explained that the same materials that fell on Mars from meteorites also fell on Earth. These likely provided the building blocks for life on our planet.

Gale Crater and Clay Minerals Preserve Organics

Curiosity, managed by NASA's Jet Propulsion Laboratory, landed in Gale crater in August 2012. This area was once a lake bed. The experiment happened in 2020 in the Glen Torridon region. This area has many clay minerals that formed when water was present. These clays are good at trapping and preserving organic material. This makes them ideal places for this kind of research.

SAM Instrument and Chemical Analysis

The Sample Analysis at Mars (SAM) instrument suite performed the analysis. Jennifer Eigenbrode, an astrobiologist at NASA's Goddard Space Flight Center and a co-author, helps lead the SAM team. SAM has made many key discoveries about Mars' chemistry, atmosphere, and potential to support life.

For this experiment, scientists used a chemical called TMAH. It breaks down larger organic molecules into smaller pieces. SAM's instruments could then examine these pieces. Curiosity only carries about two cups of TMAH, so researchers had to plan the experiment carefully and choose the best sample site.

Future Missions to Mars and Titan

The success of this method is influencing future space plans. Upcoming missions, like the Rosalind Franklin rover on Mars and the Dragonfly mission to Saturn's moon Titan, will likely use similar TMAH-based experiments to find organic compounds.

Williams stated that they now know large, complex organic molecules are preserved just below the surface of Mars. This is very promising for finding complex organic molecules that could point to life.

Deep Dive & References

• Diverse organic molecules on Mars revealed by the first SAM TMAH experiment - Nature Communications, 2026