NASA's Deep Impact Spacecraft Spots Its Quarry
Sixty-nine days before it gets up-close-and-personal with a comet,
NASA's Deep Impact spacecraft successfully photographed its quarry,
comet Tempel 1, from a distance of 64 million kilometers (39.7
Image right: Deep Impact's first image of comet Tempel 1. Image credit: NASA/JPL/UMD.
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The image, the first of many comet portraits it will take over the
next 10 weeks, will aid Deep Impact's navigators, engineers and
scientists as they plot their final trajectory toward an
Independence Day encounter.
"It is great to get a first glimpse at the comet from our
spacecraft," said Deep Impact Principal Investigator Dr. Michael
A'Hearn of the University of Maryland, College Park, Md. "With daily
observations beginning in May, Tempel 1 will become noticeably more
impressive as we continue to close the gap between spacecraft and
comet. What is now little more than a few pixels across will evolve
by July 4 into the best, most detailed images of a comet ever
||World Book @ NASA
Comet: An icy body that releases gas or dust.
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The ball of dirty ice and rock was detected on April 25 by Deep
Impact's medium resolution instrument on the very first attempt.
While making the detection, the spacecraft's camera saw stars as dim
as 11th visual magnitude, more than 100 times dimmer than a human
can see on a clear night.
"This is the first of literally thousands of images we will take of
Tempel 1 for both science and navigational purposes," said Deputy
Program Manager Keyur Patel at NASA's Jet Propulsion Laboratory,
Pasadena, Calif. "Our goal is to impact a one-meter long (39-inch)
spacecraft into about a 6.5-kilometer wide (4-mile) comet that is
bearing down on it at 10.2 kilometers per second (6.3 miles per
second), while both are 133.6 million kilometers (83 million miles)
away from Earth. By finding the comet as early and as far away as we
did is a definite aid to our navigation."
To view the comet image on the Internet, visit
Deep Impact is comprised of two parts, a "flyby" spacecraft and a
smaller "impactor." The impactor will be released into the comet's
path for a planned high-speed collision on July 4. The crater
produced by the impact could range in size from the width of a large
house up to the size of a football stadium and from 2 to 14 stories
deep. Ice and dust debris will be ejected from the crater, revealing
the material beneath.
The Deep Impact spacecraft has four data collectors to observe the
effects of the collision – a camera and infrared spectrometer
comprise the high resolution instrument, a medium resolution
instrument, and a duplicate of that camera on the impactor (called
the impactor targeting sensor) that will record the vehicle's final
moments before it is run over by comet Tempel 1 at a speed of about
37,000 kilometers per hour (23,000 miles per hour).
The overall Deep Impact mission management for this Discovery class
program is conducted by the University of Maryland. Deep Impact
project management is handled by the Jet Propulsion Laboratory. The
spacecraft was built for NASA by Ball Aerospace & Technologies
Corporation, Boulder, Colo.
For more information about Deep Impact on the Internet, visit
For more information about NASA on the Internet, visit:
D.C. Agle (818) 393-9011
Jet Propulsion Laboratory, Pasadena, Calif.
Dolores Beasley (202) 358-1753/1237