X-rays measure comet Tempel 1

UNIVERSITY PARK, Pa., July 9 (UPI) -- U.S. scientists studying the Deep Impact collision using NASA's Swift satellite report comet Tempel 1 is getting brighter and brighter each day.

X-rays provide a direct measurement of how much material was kicked up in the impact, because X-rays are created by newly liberated material lifted into the comet's thin atmosphere, and illuminated by the high-energy solar wind from the sun, Pennsylvania State University researchers said. The more material liberated, the more X-rays are produced.

Data of the water evaporation on comet Tempel 1 also may provide new insights into how solar wind can strip water from planets such as Mars, the researchers said.

"Prior to its rendezvous with the Deep Impact probe, the comet was a rather dim X-ray source," said Dr. Paul O'Brien of the University of Leicester in England. "How things change when you ram a comet with a copper probe traveling over 20,000 miles per hour. Most of the X-ray light we detect now is generated by debris created by the collision. We can get a solid measurement of the amount of material released."