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.

2003 February 18
See Explanation.  Clicking on the picture will download
 the highest resolution version available.

Candor and Ophir Chasmata
Credit: Viking Project, NASA

Explanation: First imaged by the Mariner 9 spacecraft, Valles Marineris, the grand canyon of Mars, is a system of enormous depressions called chasmata that stretch some 4,000 kilometers along the Martian equator. Looking north over the canyon's central regions, Candor chasma lies in the foreground of this spectacular view with the steep walls of Ophir chasma near the top. Surface collapse and landslides are seen to be part of the complex geologic history of these dramatic features but recent high resolution images have also revealed layered deposits within the canyon system. This picture represents a mosaic of images recorded in 1978 from Martian orbit by the Viking 1 and 2 spacecraft. The full width of the picture covers about 800 kilometers.

Tomorrow's picture: bosons on the bus

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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
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