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.

May 31, 1997
See Explanation.  Clicking on the picture will download 
 the highest resolution version available.

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 later in 1997.

Tomorrow's picture: M100: A Grand Design

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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
&: Michigan Tech. U.