NASA scientists early Monday are studying dramatic images of a collision in space, after a one-meter wide probe crashed into Comet Tempel-One - as planned. The scientists say data from the crash will help them understand comets and may shed light on the origins of our solar system.

As the first images of the impact appeared, cheers erupted at mission control in Pasadena, California late Sunday night.

The NASA Jet Propulsion Laboratory project is called "Deep Impact." Its director, Charles Elachi, says the "impactor" mission was flawless.

"From the beginning I said this is one of the most daring and risky missions that J.P.L. ever undertook and here we are successful," said Mr. Elachi. "The impact is all success and we are excited about it."

NASA enlisted space-based observatories, including the Hubble telescope, while earthbound astronomers in 20 countries monitored the cataclysmic collision 130 million kilometers away. Amateur comet-gazers gathered by the thousand in Hawaii and at other locations to glimpse of the celestial show.

The spacecraft Deep Impact released its 370-kilogram copper impactor late Saturday, California time, to begin its final journey toward Tempel-One. The collision occurred 24 hours later.

Scientists are trying to determine the size of the crater left on the comet, which could range from two to 14 stories deep and from the width of a house to the size of a football arena.

The Deep Impact flyby spacecraft carries two cameras and an infrared device to analyze spectral data, while the impactor carried a camera that sent back dramatic images of the comet until three seconds before the collision.

Scientists hope analysis of the data will help to solve a debate over the composition of comets, which are collections of rock and ice in space. Since the material beneath the surface of Tempel-One dates from the formation of the solar system, scientists hope the mission will tell them about conditions when the planets were taking shape 4.5 billion years ago.

The spectacular fireworks in space came as Americans celebrated Independence Day on the fourth of July. NASA's Rick Grammier says no message was intended.

"That being said, I obviously hope that it's made America proud to see that we overcame a lot of challenges," said Mr. Grammier. " A lot of people said we couldn't do this or wouldn't be able to pull it off."

But he says the NASA team and other project scientists made the mission happen like clockwork.

Comet Tempel-One orbits the sun in an elliptical path, completing its solar circuit every six years. The spacecraft Deep Impact was launched in January. It shares its name with a 1998 movie about a comet heading for earth, which scientists say is just a coincidence. Unlike the movie, they call their mission a "smashing success."