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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.

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

Unusual Mountain Ahuna Mons on Asteroid Ceres

Explanation: What created this unusual mountain? There is a new theory. 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. The new hypothesis , based on numerous gravity measurements, holds that a bubble of mud rose from deep within the dwarf planet and pushed through the icy surface at a weak point rich in reflective salt -- and then froze. The bright streaks are thought to be 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 in 2016 by the robotic Dawn mission . Successfully completing its mission in 2018, Dawn continues to orbit Ceres even though it has exhausted the fuel needed to keep its antennas pointed toward Earth .

Anniversary: The first APOD appeared 24 years ago today.

Date June 16, 2019
Credit Image Credit: Dawn Mission , NASA , JPL-Caltech , UCLA , MPS/DLR/IDA
Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
A service of: ASD at NASA / GSFC,
NASA Science Activation & Michigan Tech. U.