The initial ejecta that resulted when NASA's Deep Impact probe collided with comet Tempel 1.

LOS ANGELES, July 5 (Xinhuanet)-- The collision between the Deep Impact probe and comet Tempel 1 Sunday night briefly lit the dim comet's surface and exposed a section of ancient and virgin material from the comet's interior for the first time, raising the comet's ultraviolet level quickly and dramatically, said the researchers with NASA's Swift Satellite program Tuesday.

    Swift is providing the only simultaneous multi-wavelength observation of this rare event, with a suite of instruments capable of detecting optical light, ultraviolet, X-rays and gamma rays. Different wavelengths reveal different secrets about the comet.

    The rise in ultraviolet light is an evidence that the Deep Impact probe struck a hard surface of the comet nuclei, according to Sally Hunsberger, an astronomer with the Swift program at the Pennsylvania State University.

    More observations and analysis are expected in the coming days from teams at NASA and Pennsylvania State University and in Italy and the United Kingdom.

    "We have now observed this comet before, during, and after the collision," said Hunsberger. "The comparison of observations at different times, that is what was seen, when and at what wavelength, should prove to be quite interesting."

    Most of the debris observed in ultraviolet light likely came from once-icy surface material heated to 2,000 degrees by the impact. X-rays have not been detected yet but analysis will continue throughout the week.

    X-rays are expected to be emitted from newly liberated sub-surface material lifted into the comet's coma, which is then illuminated by the high-energy solar wind from the Sun. It takes about a day, however, for the material to reach the coma.

    "Some called it fireworks today, but it really was more like 'iceworks,'" said Keith Mason, who organized the Swift observations.

    "Much of the comet is ice. It's the other stuff deep inside we're most interested in -- pristine material from the formation of the solar system locked safely below the comet's frozen surface. We don't know exactly what we kicked up yet," Mason said in a statement.

    The Swift satellite, launched by NASA on Oct. 7, 2004, is designed to observe distant, natural explosions called gamma-ray bursts and create a map of X-ray sources in the universe, far moreenergetic "fireworks."

    The satellite's speed and agility, however, provides an important complement to the dozens of other world-class observatories in space and on Earth observing the Deep Impact experiment. Swift will continue to monitor the comet this week, astronomers said.

    Comets are made primarily of frozen water, methane and carbon dioxide with a small amount of minerals. They likely originate in the Oort Cloud in the outskirts of the solar system. Some scientists say that comets crashing into Earth billions of years ago brought water to our planet.

    A comet becomes visible when radiation from the Sun evaporates its outer layers, creating a coma, the thin atmosphere. Solar wind impacts the coma to form the comet's tail of dust and gas, which always points away from the Sun. Enditem