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.

March 18, 1996

Saturn with Moons Tethys and Dione
Credit: Voyager 1, JPL, NASA

Explanation: Saturn and two of its larger moons - Tethys and Dione - were photographed by the Voyager 1 spacecraft which flew by the planet in November of 1980. This picture gives an indication of Saturn's extensive ring system, which can be seen casting a shadow on the planet, as does Tethys. Saturn's rings are composed of many chunks of ice ranging in size from a pebble to a car. The rings have several large gaps, the largest of which is clearly visible in the picture and is named the Cassini Division, after its discoverer. Saturn appears brighter than most stars in the sky, and its rings can be discerned with a small telescope. A new spacecraft - Cassini - will visit Saturn and is currently scheduled for launch in 1997.

Information: The Scale of the Universe Debate in April 1996
Tomorrow's picture: The Ion Tail of Comet Hyakutake


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Authors & editors: Robert Nemiroff (GMU) & Jerry Bonnell (USRA).
NASA Technical Rep.: Sherri Calvo. Specific rights apply.
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