Astronomy Picture of the Day

Discover the cosmos! Each day we feature a different image or photograph of our fascinating universe, along with a brief explanation written by a professional astronomer.

October 18, 1995

A Storm on Saturn
Credit: NASA, HST, WFPC 2, Reta Beebe (NMSU), D. Gilmore, L. Bergeron (STScI)

Explanation: The white wisp shown on Saturn's cloud tops is actually a major storm system only discovered in December of 1994. Saturn's clouds are composed of primarily hydrogen and helium, but the storm's white clouds are actually ammonia ice crystals that have frozen upon upheaval to the top of the atmosphere. The storm may look small but has an extent similar to the diameter of the Earth. This picture is a color composite of several taken by the Hubble Space Telescope. Saturn is the second largest planet in the Solar System and has the most elaborate ring system.

Tomorrow's picture: Globular Cluster M5

Authors & editors: Robert Nemiroff (GMU) & Jerry Bonnell (USRA).
NASA Technical Rep.: Sherri Calvo. Specific rights apply.
A service of: LHEA at NASA/ GSFC