APXS Delivers 3943 Reports From Curiosity’s Mars Trek

More than a decade into its mission, NASA’s Curiosity rover is still producing fresh science thanks to a Canadian sensor that never sleeps. The Alpha Particle X-ray Spectrometer, or APXS, has now logged 1,761 samples and transmitted 3,943 individual results. Roughly the size of a Rubik’s cube, the instrument sits at the end of the rover’s arm and uses alpha particles plus X-rays to map the elemental composition of every rock it touches. In late 2024, it helped confirm the presence of nearly pure sulfur crystals inside a broken boulder—an unprecedented discovery that could reshape theories about Mars’ ancient water cycle. Operating continuously on nuclear power, APXS gathers data both day and night, unaffected by the planet’s extreme temperature swings. Canadian Space Agency officials recently extended their partnership with NASA until March 2029, guaranteeing that thousands more chemical fingerprints will reach Earth before the mission ends. Each new measurement adds another piece to the puzzle of whether Mars ever hosted microbial life.