The Strelley Pool Chert rock formation in Western Austrlia's Pilbara region is helping scientists answer questions about very early life on Earth. This picture is a composite of images acquired by the Landsat-7 satellite on May 19, 2000 (in the north), and June 23, 2001 (in the south).
Credit: NASA image created by Jesse Allen, Earth Observatory, using data obtained from the University of Maryland’s Global Land Cover Facility