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 14, 1999
See Explanation.  Clicking on the picture will download 
 the highest resolution version available.

Landsat 7 Views Planet Earth
Credit: Landsat 7 Project, NASA

Explanation: Launched last month, NASA's Landsat 7 spacecraft now orbits planet Earth. Looking down from an altitude of 700 km, Landsat 7 can map the planet's surface in visible and infrared bands and resolve features 30 meters across or smaller. For example, this striking engineering test image is a natural-looking color composite of 3 different visible wavelength bands. It nicely shows details of urban areas around San Francisco, California, USA, nestled in the surrounding terrain (north is up). Flowing blue-green colors track the spring runoff from the Sierras to the west and neighboring mountains into the bay and out into the Pacific ocean. Landsat 7 is currently performing well in its check out phase and controllers are preparing the satellite for regular operations.

Tomorrow's picture: Star Wars

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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.