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.

2017 October 9
See Explanation.  Clicking on the picture will download
 the highest resolution version available.

Unusual Mountain Ahuna Mons on Asteroid Ceres
Image Credit: Dawn Mission, NASA, JPL-Caltech, UCLA, MPS/DLR/IDA

Explanation: What created this unusual mountain? Ahuna Mons is the largest mountain on the largest known asteroid in our Solar System, Ceres, which orbits our Sun in the main asteroid belt between Mars and Jupiter. Ahuna Mons, though, is like nothing that humanity has ever seen before. For one thing, its slopes are garnished not with old craters but young vertical streaks. One hypothesis holds that Ahuna Mons is an ice volcano that formed shortly after a large impact on the opposite side of the dwarf planet loosened up the terrain through focused seismic waves. The bright steaks may be high in reflective salt, and therefore similar to other recently surfaced material such as visible in Ceres' famous bright spots. The featured double-height digital image was constructed from surface maps taken of Ceres last year by the robotic Dawn mission.

Open Science: Browse 1,500+ codes in the Astrophysics Source Code Library
Tomorrow's picture: zodiac pinnacles


< | Archive | Submissions | Index | Search | Calendar | RSS | Education | About APOD | Discuss | >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Phillip Newman Specific rights apply.
NASA Web Privacy Policy and Important Notices
A service of: ASD at NASA / GSFC
& Michigan Tech. U.