The oldest material on Earth which has yet been dated by man is a zircon
mineral of 4.4 billion years old from a sedimentary gneiss in the Jack
Hills of the Narre Gneiss Terrane of Australia. It is the most ancient
fragment of the earth’s crust so far identified, formed approximately 150
million years after the planet itself. In August of 2007, scientists
reported finding the world’s oldest diamond crystals, encased inside the
zircon crystals.
The image was acquired October 12, 2004, covers an area of 26.6 x 34.2 km,
and is located near 26.2 degrees south latitude, 117.1 degrees east
longitude.
With its 14 spectral bands from the visible to the thermal infrared
wavelength region and its high spatial resolution of 15 to 90 meters
(about 50 to 300 feet), ASTER images Earth to map and monitor the changing
surface of our planet. ASTER is one of five Earth-observing instruments
launched December 18, 1999, on NASA's Terra satellite. The instrument was
built by Japan's Ministry of Economy, Trade and Industry. A joint
U.S./Japan science team is responsible for validation and calibration of
the instrument and the data products.
The broad spectral coverage and high spectral resolution of ASTER provides
scientists in numerous disciplines with critical information for surface
mapping and monitoring of dynamic conditions and temporal change. Example
applications are: monitoring glacial advances and retreats; monitoring
potentially active volcanoes; identifying crop stress; determining cloud
morphology and physical properties; wetlands evaluation; thermal pollution
monitoring; coral reef degradation; surface temperature mapping of soils
and geology; and measuring surface heat balance.
The U.S. science team is located at NASA's Jet Propulsion Laboratory,
Pasadena, Calif. The Terra mission is part of NASA's Science Mission
Directorate.
More information about ASTER is available at http://asterweb.jpl.nasa.gov/.