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.

October 30, 1999
See Explanation.  Clicking on the picture will download 
 the highest resolution version available.

Mars Rocks, Sojourner Rolls
Credit: IMP Team, JPL, NASA

Explanation: This sharp colour image featuring Mars rock Yogi and the rolling Sojourner robot shows off Yogi's two-toned surface. Yogi appears to be leaning into the prevailing winds causing some to suggest that its colour contrast may be caused by the accumulation of rust coloured dust on its windward face. The Pathfinder spacecraft, now the Sagan Memorial Station, has ended the primary mission phase after returning a scientific bonanza from the surface of Mars. The Sojourner robot rolled hundreds of feet on the martian surface, circumnavigated the lander, and produced a wealth of data and images. Mars Pathfinder and Soujourner landed on July 4, 1997 and lasted about 3 months, well beyond their designed lifetime.

Tomorrow's picture: Eye of Cat


< Archive | Index | Search | Calendar | Glossary | Education | About APOD >

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.