Earth comes in for its close-up with NASA’s Advanced
Spaceborne Thermal Emission and Reflection Radiometer (ASTER)
— the “zoom lens” of NASA’s Terra satellite — and now image
data from the instrument are available to the public.

“ASTER is a general-purpose instrument,” says Dr. Michael
Abrams of NASA’s Jet Propulsion Laboratory, the ASTER
associate science team leader. “It has capabilities for a
variety of users and applications. It can map the planet’s
surface and how it changes with time, and can determine the
characteristics of land and water surfaces.” The instrument
has 14 spectral bands, extremely high spatial resolution and
stereo imaging capabilities.

Built in Japan for the Ministry of International Trade
and Industry, ASTER is one of several Earth-observing
instruments on the Terra satellite, launched in December 1999.
Part of NASA’s Earth Observing System, Terra flies in a Sun-
synchronous polar orbit. The ASTER instrument can revisit any
place on Earth at least every 16 days, and researchers will be
able to request that ASTER take images of specific areas.

One of ASTER’s primary goals is to acquire a one-time
cloud-free image of the entire land surface of Earth, an
important baseline against which environmental change, both
natural and human-induced, can be measured. Environmental
monitoring using ASTER data is already underway in studies of
glaciers, coral reefs and deforestation. ASTER’s land-use
applications include acquiring basic information about the
composition and distribution of materials on Earth’s surface.
The observations are helping identify new mineral and fossil
fuel deposits in poorly explored regions, monitoring land use
and land cover, and providing information on agricultural and
urban development in growing areas of population. With its
ability to detect volcanic gas emissions and thermal change,
the instrument is also proving to be an important new tool for
monitoring volcanoes and helping improve predictions of their
sometimes deadly eruptions.

A joint U.S.-Japan science team is responsible for
instrument design, calibration and validation. More
information about ASTER is available online at .

ASTER provides data in scenes of about 60 x 60 kilometers
(37 x 37 miles) with spatial resolutions between 15 and 90
meters (49 and 295 feet). ASTER data will be processed,
archived and distributed by the U.S. Geological Survey EROS
Data Center’s Distributed Active Archive Center in Sioux
Falls, S.D. For information, see .

Images associated with this release are available at .

The Terra spacecraft, the flagship of a fleet of
satellites dedicated to understanding our global environment,
is part of NASA’s Earth Sciences Enterprise, a long-term
research program dedicated to understanding how human-induced
and natural changes affect our world.

JPL is a division of the California Institute of
Technology in Pasadena.