The space agency successfully smashed into the comet early Monday in the hopes of examining its frozen core for ice and rock left over from the early solar system.
When the washing machine-sized probe, or "impactor," had its rendezvous with the comet, the collision set off a brighter than expected burst of light in the sky about 130 million kilometres from Earth.
The copper impactor took photographs of the comet up to three seconds before the crash.
Photo taken 16 seconds after initial collision with comet Tempel 1. (Photo courtesy NASA/JPL-Caltech/UMD)
"It was probably a soft surface," said Pete Schultz of Brown University, a co-investigator on the project, based on an early analysis of the images.
Michael A'Hearn, an astronomer at the University of Maryland and the principal investigator for the mission, compared the comet's shape to that of a muffin or loaf of bread. Along with craters, the comet also appears to have shiny areas that are poorly understood.
Scientists won't be able to tell how large a crater was formed by the impact until the dust settles, which could take hours or weeks, A'Hearn said. The team is confident the collision was a success because they can see the crater's shadow in the images.
Mike A'Hearn
By combining the information with what's already known about our solar system, scientists will get a better idea of what happened, said David Dodge, an astronomer at H.R. MacMillan Space Centre in Vancouver.
Aside from studying the comet's makeup, scientists may have gained clues to divert a comet should one head towards Earth.
"The knowledge that comes out of this is important to understanding how to deflect a comet," said A'Hearn. "Any serious attempt to deflect a comet with an impact, however, requires a much, much larger impact than we delivered."
The crash did not make much difference to the comet's orbit and the experiment never posed a danger to Earth, NASA said.
The impactor's mothership, Deep Impact, sent back data on the collision to Earth.
More images of the crash are expected from observatories on Earth and in space. Scientists plan to pore over the data for months.
European scientists plan to land a probe on a comet in 2014. A spiked lander will use harpoons to claw into Comet 67 P/Churyumov-Gerasimenko.
