APOD: 2026 October 9 – Stickney Crater

APOD Science APOD APOD: 2026 October 9… Today’s APOD Archive Submissions Index Search Calendar RSS Education About Discuss APOD Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. Stickney Crater Explanation: Stickney Crater, the largest crater on the martian moon Phobos, is named for Chloe Angeline Stickney Hall, mathematician and wife of astronomer Asaph Hall. Asaph Hall discovered both the Red Planet’s moons in 1877. Over 9 kilometers across, Stickney is nearly half the diameter of Phobos itself, so large that the impact that blasted out the crater likely came close to shattering the tiny moon. This enhanced-color image of Stickney and surroundings was recorded by the HiRISE camera onboard the Mars Reconnaissance Orbiter as it passed within some six thousand kilometers of Phobos in March of 2008. Even though the surface gravity of asteroid-like Phobos is less than 1/1000th Earth’s gravity, streaks suggest loose material slid down inside the crater walls over time. Light bluish regions near the crater’s rim could indicate a relatively freshly exposed surface. The origin of the curious grooves along the surface is mysterious but may be related to tidal stresses experienced by close-orbiting Phobos or the crater-forming impact itself. Tomorrow’s picture: farside Date: October 9, 2026 Credit: HiRISE , MRO , LPL (U. Arizona) , NASA Authors & editors: Jerry Bonnell, Cecilia Chirenti, Robert Nemiroff, Keighley Rockcliffe A service of: ASD at NASA / GSFC , NASA Science Activation & Michigan Tech. U. Random APOD Generator Yesterday’s Image APOD: 2026 October 8 – The Saturn System Smörgåsbord Tomorrow’s Image International observational observatories, orbital space missions, and planetary research institutes are producing unprecedented empirical datasets that challenge foundational paradigms across astrophysics, planetary geology, and fundamental physics.