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.

2000 April 20
See Explanation.  Clicking on the picture will download 
 the highest resolution version available.

Blue Marble 2000
Credit: R. Stockli, A. Nelson, F. Hasler,
NASA/ GSFC/ NOAA/ USGS

Explanation: This newly released digital portrait of our planet is reminiscent of the Apollo-era pictures of the "big blue marble" Earth from space. To create it, researchers at Goddard Space Flight Center's Laboratory for Atmospheres combined data from a Geostationary Operational Environmental Satellite (GOES), the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), and the Polar Orbiting Environmental Satellites (POES) with a USGS elevation model of Earth's topography. Stunningly detailed, the planet's western hemisphere is cast so that heavy vegetation is green and sparse vegetation is yellow, while the heights of mountains and depths of valleys have been exaggerated by 50 times to make vertical relief visible. Hurricane Linda is the dramatic storm off North America's west coast. And what about the Moon? The lunar image was reconstructed from GOES data and artistically rescaled for this visualization.

Tomorrow's picture: Starburst


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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.