Comet Tempel 1 has received more attention than any other comet in the universe — as far as we know.

On July 4, 2005, a spacecraft named Deep Impact released an 820-pound probe into the comet’s path. The impact made a crater on the comet’s surface and sent a plume of dust into space, while the spacecraft took pictures from below. Other instruments studied the dust plume to determine what made up the comet, but there was so much dust the spacecraft couldn’t see the crater.

Too bad.

But wait. Another spacecraft, called Stardust, had finished its mission at another comet, called Wild 2.  Stardust still had lots of pep and no place to go.

“Let’s put Stardust back to work,” NASA scientists said. So they planned another mission for Stardust, now called Stardust-NExT — for New Exploration of Tempel 1. It would get another look at Comet Tempel 1, which had finished its trip around the sun since its meeting with Deep Impact.

On Feb. 14, 2011, NASA again met up with Comet Tempel 1. By this time, Tempel 1 was a little older and a little more “worn out.” Like all comets, when it was closest to the sun in its orbit, it warmed up and some of its surface evaporated, creating the comet’s coma and tail.

Stardust-NExT found the 500-foot crater left by Deep Impact, and scientists are studying the crater’s rim to see whether it’s worn down. They saw that a mound of material had settled into the center of the crater and other formations also had changed. Scientists will continue to study the information from the two missions to Comet Tempel 1. What else will they discover about comets?

The Space Place has lots of fun facts, games and puzzles about comets and NASA’s comet missions. Go to and enter “comets” in the “Find it @ Space Place” field.

This article was written by Diane K. Fisher.  It was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.