By Paul Hoversten WASHINGTON -- Just in time for Earth Day comes a view of the planet in unprecedented detail.
Scientists on Wednesday released the first comprehensive pictures from Terra, NASA's flagship Earth-observing satellite, which was launched into orbit late last year.
Among the images were stunning views of parts of North America that revealed layers of vegetation, carbon monoxide and reflected solar radiation.
This short-wave infrared, false-color image of Mauna Loa volcano in Hawaii, taken by Terra, depicts lava flows in uniform dark colors.
Parts of Nevada, California and Hawaii were shown in brilliant multi-spectral colors that simultaneously highlighted their surface details, moisture content, temperature and cloud cover.
Other pictures Wednesday showed fresh stripes of volcanic ash around neighborhoods near the Japan's Mount Usu, dust and haze over the Indian subcontinent and a swath of clouds hugging the Appalachian Mountain range in the eastern United States.
The $1.3 billion Terra is the first satellite to monitor daily on a worldwide scale how the Earth's atmosphere, land, oceans, solar radiation and life influence each other.
Its scientific goals are to determine how carbon from all living things cycles through the atmosphere and how Earth's climate changes over time.
"Terra is measuring the Earth's vital signs, many of them for the first time," said Yoram Kaufman, project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland.
"The Earth needs this comprehensive physical exam. Doctor's orders," he said.
But Kaufman said it was too soon for a prognosis on Earth's condition.
"We expect to have the first significant science results in a year," he said.
Terra snapped this long-wave radiation view of the United States.
More than 1,000 scientists from around the world are sifting the data from Terra, which they consider as a sort of Hubble Space Telescope aimed at Earth. Their hope is that Terra can broaden our understanding of the planet in much the same the way as Hubble has opened up new views on the cosmos.
Terra is circling Earth in an orbit around its poles at an altitude of 450 miles (750 kilometers). Aboard the satellite are five instruments -- three from the United States and one each from Japan and Canada -- to measure such things as moisture, vegetation and sunlight.
The combined data will give scientists a better understanding of how Earth's components -- from its atmosphere to its oceans -- work together as a single system.
As an example, scientists at Wednesday's briefing at NASA Headquarters unveiled a montage of images of the Himalayan plateau captured by Terra on a single pass from orbit.
First, the satellite saw heavy moisture in the atmosphere, typical for the Himalayas this time of year. That brought rain, which in turn made vegetation grow.
Then Terra saw high levels of haze generated by automobiles and industries on the Himalayan plateau, home to half a billion people. That led to high levels of carbon monoxide over the Indian subcontinent and changes in the amount of sunlight reflected back into space -- a "greenhouse effect" in the making.
"This ability to use these instruments togetherwill revolutionize our study of Earth," Kaufman said.
Water vapor is by far the dominant greenhouse gas. Terra's MODIS instrument can directly measure concentrations of the gas down through a total column of atmosphere, which is particularly useful for studies of regional and global hydrological cycles.
On a practical level, data from Terra may help in managing crops and coastal fisheries and assessing natural hazards like earthquakes, floods and fires.
About the size of a school bus, Terra will record spectral data from the visible to the infrared, covering the entire surface of Earth every 16 days. Each day Terra will collect enough data -- 850 gigabytes -- to fill 100,000 encyclopedia volumes.
Terra was launched December 18, 1999, aboard an Atlas/Centaur 2-AS rocket from Vandenberg Air Force Base, California. It reached its final orbit in February and is expected to be operational for six years.
Its sister satellite, Aqua, is scheduled to be launched late this year. By the year 2005, NASA expects to have a fleet of 30 Earth-science satellites circling the planet.
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