Curiosity's 2020 Martian rock sample yields seven organic molecules never before found on Mars

Key facts

• Nasa's Curiosity rover drilled a Martian rock sample nicknamed Mary Anning 3 from Mount Sharp in October 2020, and years of analysis identified 21 carbon-containing molecules, the most varied collection ever found on Mars, including seven organic molecules never detected on the planet before.
• The findings were published in Nature Communications by lead author Amy Williams of the University of Florida.
• One new discovery is a nitrogen heterocycle, a carbon ring containing nitrogen, never before found on the Martian surface or confirmed in Martian meteorites, and considered a chemical precursor to ribonucleic acid (RNA) and deoxyribonucleic acid (DNA).
• Another standout molecule is benzothiophene, which contains carbon and sulphur and has appeared in many meteorites thought to have seeded prebiotic chemistry across the early solar system.
• The sample came from a clay-rich part of Mount Sharp that lakes and streams covered billions of years ago; clay minerals are especially good at preserving organic compounds.
• Curiosity's onboard laboratory, Sample Analysis at Mars (SAM), built by Nasa's Goddard Space Flight Centre, used wet chemistry with tetramethylammonium hydroxide for the first time on Mary Anning 3, which was the highest-value reserved solvent.
• Scientists validated the technique on the Murchison meteorite, which is more than four billion years old, showing the Martian molecules could have formed from the breakdown of even more complex compounds.
• Nasa Goddard supplied components, including the mass spectrometer, for the Mars Organic Molecular Analyser on the European Space Agency's Rosalind Franklin Mars rover, and a similar Dragonfly Mass Spectrometer will explore Saturn's moon Titan aboard Nasa's Dragonfly rotorcraft.