NASA’s Curiosity Rover Sniffs Martian Air: No Clear Methane Found, But Clues to a Lost Atmosphere
NASA’s Curiosity rover, launched on November 26, 2011, and landing on Mars’ Gale Crater on August 5, 2012, has been exploring the Red Planet for nearly 13 years. One of its important tasks has been to analyze the Martian atmosphere for methane—a gas often associated with biological activity on Earth. Using its Sample Analysis at Mars (SAM) instrument suite, Curiosity has repeatedly “gulped” Martian air to detect methane and other gases. Early reports of methane spikes have since been questioned, with more recent data and observations from orbiters like ESA’s Trace Gas Orbiter showing no confirmed methane presence, suggesting any methane on Mars is extremely rare, localized, or transient.
While the methane mystery remains unresolved, Curiosity’s instruments have revealed important clues about Mars’ atmospheric history. SAM’s Quadrupole Mass Spectrometer detected that carbon dioxide in Mars’ atmosphere contains a higher proportion of heavier carbon isotopes than expected from a pristine atmosphere. This isotopic signature indicates that Mars has lost a large portion of its original atmosphere over billions of years, likely because lighter isotopes escaped into space while heavier ones remained. Scientists estimate that more than half of Mars’ original carbon dioxide may have been lost, explaining why today’s atmosphere is so thin—about 1% the density of Earth’s—and dominated by carbon dioxide (around 96%).
In addition, Curiosity has discovered ancient organic molecules in Martian rocks, including complex hydrocarbons, which hint at past chemical processes that could have supported life. Although these organics are not direct evidence of life, they provide valuable insights into Mars’ past habitability.
Curiosity’s mission, initially planned for two Earth years, has been extended indefinitely and continues to provide critical data as of 2025. The rover’s ongoing atmospheric measurements aim to detect any seasonal or episodic methane releases and better understand the interactions between Mars’ surface and atmosphere.
In summary, while Curiosity has yet to confirm methane or life on Mars, its findings about atmospheric loss and organic chemistry are key to unraveling the planet’s history and potential for habitability.
This version integrates Curiosity’s launch and landing dates, mission duration, and the latest scientific understanding of methane and atmospheric loss on Mars, making it clear and current for a science blog audience[1][2][3][7][8].
Read More
[1] https://en.wikipedia.org/wiki/Curiosity_(rover)
[2] https://www.jpl.nasa.gov/missions/mars-science-laboratory-curiosity-rover-msl/
[3] https://en.wikipedia.org/wiki/Timeline_of_Mars_Science_Laboratory
[4] https://science.nasa.gov/mission/msl-curiosity/location-map/
[5] https://www.lpi.usra.edu/features/ala_msl/landing/index.shtml
[6] https://earthsky.org/space/mars-curiosity-rovers-seven-minutes-of-terror/
[7] https://www.space.com/17963-mars-curiosity.html
[8] https://nasa3d.arc.nasa.gov/detail/mars-rover-curiosity