Story of Blue Marble 2000
Recalling the famous Apollo-era pictures of Earth taken by lunar
astronauts, this digital image is a spectacular portrait of the Western
Hemisphere at the time of one of the strongest hurricanes ever observed in
the Eastern Pacific.
This combination of science, engineering and artistry was generated by
researchers in the Laboratory for Atmospheres at NASA's Goddard Space
Flight Center, Greenbelt, MD, using data from three different
Earth-observing satellite instruments.
The research team's goal was to assemble an image that recreates the
visceral impact of viewing Earth from space with human eyes. The prominent
storm raging off the west coast of North America is Hurricane Linda. Other
obvious features include the shallow waters of the Caribbean and sediments
around the mouth of the Amazon River.
The underlying image of the full disk of Earth and its clouds was taken on
September 9, 1997, by a Geostationary Operational Environmental Satellite
(GOES) operated by the U.S. National Oceanic and Atmospheric Administration
(NOAA), and built by NASA. The ocean color data was collected in late
September and early October 1997 by NASA's Sea-viewing Wide Field-of-view
Sensor (SeaWiFS) satellite. The land color is portrayed by a vegetation
index calculated using data collected from September 9-19, 1997, by
Advanced Very High Resolution Radiometer (AVHRR) instruments carried aboard
NOAA's Polar Orbiting Environmental Satellites (POES).
These data are draped across a digital elevation model of Earth's
topography from the U.S. Geological Survey. The complete computer image
file is 26 megabytes, making it one of the most detailed Earth images ever created by NASA!
The researchers chose to translate the digital data over land into a color
scheme where heavy vegetation is green and sparse vegetation is yellow.
The heights of mountains and depths of valleys have been exaggerated by 50
times their actual levels so that vertical relief is visible. The shadows
for the mountains were calculated from the exaggerated heights.
The presence of the Moon in this image is an artistic addition. The lunar
image was collected by GOES in September 1994, and has been magnified to
about twice its relative size.
This image was created by Reto Stockli with the help of Alan Nelson, under
the leadership of Fritz Hasler.
This image along with other visualizations of hurricanes and global datasets
are available at various resolutions at:
http://rsd.gsfc.nasa.gov/rsd
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