It was the first time a spacecraft had ever touched the surface of a comet, igniting brief Independence Day weekend fireworks in space.
The successful strike 83 million miles away from Earth occurred at 10:52 p.m. PDT, according to mission control at NASA's Jet Propulsion Laboratory in Pasadena. Scientists on the mission — called Deep Impact, like the movie — erupted in applause and exchanged hugs.
"A lot of people said we couldn't do this or wouldn't be able to pull it off," project manager Rick Grammier said later at a predawn Monday news conference. "It happened like clockwork and I think that's something to be proud of on America's birthday."
The cosmic smash-up did not significantly alter the comet's orbit around the sun and NASA said the experiment doesn't pose any danger to Earth.
An image by the mothership, which had released the barrel-sized "impactor" probe on its suicide mission 24 hours earlier, showed a bright spot in the lower section of the comet where the collision occurred. A cloud of debris was hurled into space. When the dust settles, scientists hope to peek inside the comet's frozen core — a composite of ice and rock left over from the early solar system.
CBS News Correspondent Bill Whitaker reports that the kamikaze impactor kept sending back images until three seconds before smashing into the comet with the energy of five tons of TNT.
"We hit it just exactly where we wanted to," co-investigator Don Yeomans said.
"This was an amazingly difficult technological challenge to pull off," said CBS News Space Consultant Bill Harwood on CBS News' The Early Show. "It hit at 23,000 mile an hour."
Among stargazers awaiting the event across the country were more than 10,000 people at Hawaii's Waikiki Beach who saw the impact on a giant movie screen. Some skywatchers said they even spotted a red streak across the southwestern sky that lasted several seconds.
"It's almost like one of those science fiction movies," said Steve Lin, a Honolulu physician as his 7-year old son, Robi, zipped around his beach blanket.
Bob Joseph, faculty chair at the University of Hawaii Institute for Astronomy, commended NASA scientists. "Nobody has ever done an experiment like this ever in the history of the world," he said.
The impact caused the comet — a pickle-shaped body half the size of Manhattan — to shine six times brighter than normal, said Michael A'Hearn, principal investigator of the $333 million project.
Scientists had compared the impactor probe's journey toward the path of the Tempel 1 comet as similar to standing in the middle of a road and being hit by a semi-truck roaring at 23,000 mph. They have estimated the crater may range in size from a large house to a football stadium with a depth of two to 14 stories deep.