Images from NASA's "Landsat" series of satellites have provoked awe and dismay for 29 years. The satellites-the nation's chief source of earth surface images-have revealed previously undetected earthquake faults, rain forest destruction and the melting of polar ice caps.

Future images promise to reveal even more. Last November, NASA launched a next-generation prototype satellite, Earth Observing-1, which carries test versions of instruments up to ten times better at detecting subtle differences in brightness and 25 times better at detecting colors. The first images are now in hand, and the space agency says the imagers show promise as a replacement to Landsat's 1970s-era equipment. Says NASA mission scientist Stephen Ungar, "It is conclusively proved that this technology works."

Earth Observing-1 "sees more crisply in a package that is cheaper and lighter," says physicist Don Lencioni, who helped develop one of the satellite's three land-imaging instruments at MIT's Lincoln Laboratory in Lexington, MA. In black-and-white mode, the new system can resolve features as small as 10 meters wide, instead of the old 15 meters.

This improved vision should allow for better monitoring of ocean pollution and crop health. And because the new satellite costs less than half of a Landsat, it could be feasible to send more than one into orbit. This would allow for more frequent checks on events like forest fires; Landsat images the planet only once every 16 days.