Physicist Louis Frank presented the new findings from his instrument on Polar at the spring meeting of American Geophysical Union in Baltimore, Maryland on May 28, 1997. In brief, the trails of light from the small comets have now been detected by both far ultraviolet and visible light cameras aboard Polar and at distances ranging from 600 to 15,000 miles above Earth.

"The Polar results definitively demonstrate that there are objects entering Earth's upper atmosphere that contain a lot of water," says University of Michigan professor Thomas Donahue, one of the world's leading authorities on atmospheric science. "These results certainly vindicate Lou Frank's earlier observations."

But the wealth of discoveries coming from Polar have even surprised Louis Frank. In a first for astronomy, the wide-angle, far-ultraviolet Earth Camera, one of three cameras on Polar's Visible Imaging System (VIS), obtained dramatic images of some small comets disintegrating 5,000-to-15,000 miles above Earth. Frank had not expected to be able to see these objects breaking up at such great distances from Earth.

This spectacular disruption (at right) of a small comet the size of a two-bedroom house took place 5,000 to 15,000 miles above the Atlantic Ocean at 2228 UT on September 26, 1996. A view of Earth at the time of the event has been superposed onto the far-ultraviolet image as a frame of reference. This unusually bright and long-lived trail, which was captured by Earth Camera aboard NASA's Polar spacecraft, ends over Germany.

"Images like this show that we have a large population of objects in Earth's vicinity that have not been detected before," notes Frank.

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