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.

2023 February 5
A large tan ball with multiple complex grooves is pictured.
A sliver on the far right side appears almost white. 
Please see the explanation for more detailed information.

Enceladus by Saturnshine
Image Credit: NASA; ESA, JPL, Cassini Imaging Team, SSI; Colour Composite: Gordan Ugarkovic

Explanation: This moon is shining by the light of its planet. Specifically, a large portion of Enceladus pictured here is illuminated primarily by sunlight first reflected from the planet Saturn. The result is that the normally snow-white moon appears in the gold colour of Saturn's cloud tops. As most of the illumination comes from the image left, a labyrinth of ridges throws notable shadows just to the right of the image centre, while the kilometre-deep canyon Labtayt Sulci is visible just below. The bright thin crescent on the far right is the only part of Enceladus directly lit by the Sun. The featured image was taken in 2011 by the robotic Cassini spacecraft during a close pass by the enigmatic moon. Inspection of the lower left part of this digitally sharpened image reveals plumes of ice crystals thought to originate in a below-surface sea.

Tomorrow's picture: stars and dust


< | 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,
NASA Science Activation
& Michigan Tech. U.