NASA Curiosity rover discovers rocks containing seven new organic molecules on Mars

Rocks discovered by NASA’s Mars rover Curiosity contain the “most diverse collection” of the building blocks of life ever seen on Mars, including seven species never before found on Mars, a new study confirms.

Curiosity discovered the rock in 2020, and when it drilled into it, it found it contained organic molecules, including carbon, an element that is friendly to life. Although scientists cannot yet prove whether the molecules were formed by biological or geological processes, their discovery adds new evidence to the theory that ancient Mars was habitable.

“Their findings provide new confirmation that ancient Mars had the right chemistry to support life,” officials at NASA’s Jet Propulsion Laboratory (JPL), which manages the mission, wrote about the organic matter. “Furthermore, these molecules join the list of compounds known to be preserved in rocks even after billions of years of exposure to radiation on Mars, and over time these molecules can degrade.”

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Along the coast of Mars

A new analysis published April 21 in the journal Nature Communications shows that the rock sample contains 21 carbon-containing molecules, including seven never seen before on Mars. The newly discovered molecules, which include nitrogen heterocycles (a precursor to RNA and DNA) and benzothiophenes, may have been key to bringing life-friendly chemistry to the solar system’s planets aboard meteorites, the authors write.

The specimen was named Mary Anning 3, after the British paleontologist famous for discovering the first ichthyosaur and plesiosaur fossils. Similar to the aquatic fossil environments that Anning sought, Martian organic matter has been found in regions of Mars that were filled with lakes and rivers before the planet dried up billions of years ago.

“This oasis was flooded and drained many times during Earth’s ancient times, eventually enriching the area with clay minerals that are particularly good at preserving organic compounds,” JPL officials wrote.

A lifetime of drilling

Last year, Curiosity also discovered the largest organic molecule ever discovered on Mars. These were “long chain” hydrocarbons such as decane, undecane, and dodecane.

These organic discoveries in 2020 and 2025 used Curiosity’s instrument called Sample Analysis at Mars (SAM). Curiosity first uses a robotic arm to excavate rock. The rock is then turned into a powder sample and the powder is dropped into the SAM. The instrument includes a high-temperature oven that heats the powder, allowing it to measure the composition of the gases inside the spacecraft.

The SAM also includes a small cup containing a solvent that allows you to perform “wet chemistry.” The Mary Anning 3 sample was the first to use tetramethylammonium hydroxide (TMAH). Tetramethylammonium hydroxide (TMAH) is a substance that breaks down organic molecules, and although Curiosity only carried two cups of it, this sample was considered to be of the highest value.

Curiosity’s discovery was verified on Earth using the Murchison meteorite, a space rock well known to science. The Murchison meteorite is 4 billion years old and contains organic molecules.

“Murchison’s samples exposed to TMAH were found to destroy molecules much larger than some of those seen on Mary Anning 3, including benzothiophene,” JPL officials wrote. “This result proves that the Martian molecules found on Mary Anning 3 could have been produced from the breakdown of more complex compounds associated with life.”

Curiosity, which has been on Mars since 2012, recently used its last TMAH cup on “a spiderweb-like box ridge formed by ancient groundwater,” according to JPL. Results will be reported in a future study.

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