NASA has been receiving well-deserved praise for the success of its Deep Impact mission, in which its space probe of that name hit its target, Comet Tempel 1, on July 4. There were many non-believers that a mission like Deep Impact's could be successful.

The mission was a milestone for NASA, which hopes the experiment will answer basic questions about the origins of the solar system.

The mission also has given scientists some information about how they might one day stop a comet if one were to threaten Earth. However, they would need a much larger strike than Deep Impact to make a significant dent in turning a comet off-course, according to Michael A'Hearn, an astronomer at the University of Maryland and Deep Impact principal investigator.

The Deep Impact-Tempel 1 collision occurred 83 million miles from Earth. Deep Impact was launched on its mission Jan. 12 from Cape Canaveral, Fla., and traveled 268 million miles to get the comet in its sights.

A day before the space smash-up, Deep Impact released its "impactor" probe and pointed it toward the comet. The probe made a 24-hour solo flight toward the comet, heading for the fiery rendezvous.

The energy produced from the impact was equivalent to exploding five tons of dynamite, and it caused the comet to shine six times brighter than normal.

Deep Impact was a milestone for the U.S. space agency, because no other space mission has flown this close to a comet. In 2004, NASA's Stardust craft flew within 147 miles of Comet Wild 2 en route back to Earth carrying interstellar dust samples.

After Deep Impact's successful rendezvous, David Southwood, of the European Space Agency, said "the Deep Impact mission brought the world together in an excellent opportunity to make a new step into the advancement of cometary science." He's correct.

Meanwhile, the ESA is especially interested in the U.S. mission because that agency will attempt to rendezvous with a comet in 2014.