NASA EPOXI Flyby Reveals New Insights Into Comet Features
WASHINGTON -- NASA's EPOXI mission spacecraft successfully flew past comet Hartley 2 at 10 a.m. EDT Thursday. Scientists say initial images from the flyby provide new information about the comet's volume and material spewing from its surface."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."
EPOXI is an extended mission that uses the already in-flight Deep
Impact spacecraft. Its encounter phase with Hartley 2 began at 4 p.m.
EDT on Nov. 3, when the spacecraft began to point its two imagers at
the comet's nucleus. Imaging of the nucleus began one hour later.
"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."
Images from the EPOXI mission reveal comet Hartley 2 to have 100 times
less volume than comet Tempel 1, the first target of Deep Impact.
More revelations about Hartley 2 are expected as analysis continues.
Initial estimates indicate the spacecraft was about 435 miles from the
comet at the closest-approach point. That's almost the exact distance
that was calculated by engineers in advance of the flyby.
"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 at NASA's Jet Propulsion Laboratory
(JPL) in Pasadena, Calif. "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."
The name EPOXI is a combination of the names for the two extended
mission components: the Extrasolar Planet Observations and
Characterization (EPOCh), and the flyby of comet Hartley 2, called
the Deep Impact Extended Investigation (DIXI). The spacecraft has
retained the name Deep Impact. In 2005, Deep Impact successfully
released an impactor into the path of comet Tempel 1.
NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the EPOXI
mission for NASA's Science Mission Directorate. The spacecraft was
built for NASA by Ball Aerospace & Technologies Corp., in Boulder, Colo.
For more information about EPOXI, visit:
http://www.nasa.gov/epoxi
http://epoxi.umd.edu/
For information about NASA and agency programs, visit:
http://www.nasa.gov
Source: NASA
