Washington, Sep 21 (IANS) The US space agency has announced an end to its eight-year Deep Impact mission that included an unprecedented impact, comet flybys and the return of approximately 500,000 images of celestial objects, Xinhua reported Friday.

Deep Impact was most travelled comet research mission in history, going about 4.7 billion miles (7.58 billion km).

The project team at NASA's Jet Propulsion Laboratory (JPL) gave up on the Deep Impact after being unable to communicate with the spacecraft for more than a month. The last communication with the probe was Aug 8.

"Deep Impact has been a fantastic, long-lasting spacecraft that has produced far more data than we had planned," Mike A'Hearn, Deep Impact principal investigator at the University of Maryland said in a statement. "It has revolutionised our understanding of comets and their activity."

Launched in January 2005, the spacecraft first made worldwide headlines July 4, 2005, when it released a refrigerator-sized impactor to collide spectacularly with comet Tempel 1, giving scientists their first-ever view of pristine material from inside a comet.