Deep Impact craft gets close to second comet

Posted by Emma Woollacott

NASA's Deep Impact spacecraft got a closeup view of comet Hartley 2 yesterday, getting within 435 miles of the comet.

Scientists say the initial images from the flyby provide new information about the comet's volume and the material spewing from its surface. It's only the fifth time a comet has been viewed at close quarters.

They show Hartley 2 to be just one hundredth of the size of comet Tempel 1, the first comet to be studied close-up by Deep Impact. More discoveries are expected as analysis of the compet, which consists of ancient material from the edge of the solar system, continues.

"Early observations of the comet show that, for the first time, we may be able to connect activity to individual features on the nucleus," said EPOXI principal investigator Michael A'Hearn of the University of Maryland, College Park. "We certainly have our hands full. The images are full of great cometary data, and that's what we hoped for."

Getting so close to the comet in safety was an achievement in itself.

"It is a testament to our team's skill that we nailed the flyby distance to a comet that likes to move around the sky so much," said Tim Larson, EPOXI project manager.

"While it's great to see the images coming down, there is still work to be done. We have another three weeks of imaging during our outbound journey."

Comet Hartley 2 was first spotted in 1986 by British scientist Malcolm Harley, who was working as a quality controller at Siding Spring Observatory's UK Schmidt telescope in New South Wales, Australia. Seeing smudges on a series of images, he realized that they represented a comet rather than a fault with the photography.

"The spacecraft has provided the most extensive observations of a comet in history," said Ed Weiler, associate administrator for NASA's Science Mission Directorate at the agency's headquarters in Washington.

"Scientists and engineers have successfully squeezed world-class science from a re-purposed spacecraft at a fraction of the cost to taxpayers of a new science project."