[meteorite-list] NASA's Deep Impact Generates Its Own Spectacular Photo Flash

[Ron Baalke]

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIFORNIA 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov

DC Agle (818) 393-9011
Jet Propulsion Laboratory, Pasadena, Calif.

Dolores Beasley (202) 358-1753
NASA Headquarters, Washington 							

Lee Tune (301) 405-4679
University of Maryland, College Park

NEWS RELEASE: 2005-110 				July 4, 2005

NASA'S DEEP IMPACT GENERATES ITS OWN SPECTACULAR PHOTO FLASH

The hyper-speed demise of NASA's Deep Impact probe generated 
an immense flash of light, which provided an excellent light 
source for the two cameras on the Deep Impact mothership.  
Deep Impact scientists theorize the 820-pound impactor vaporized 
deep below the comet's surface when the two collided at 1:52 am 
July 4, at a speed of about 10 kilometers per second 
(6.3 miles per second or 23,000 miles per hour). 

"You can not help but get a big flash when objects meet at 
23,000 miles per hour," said Deep Impact co-investigator Dr. 
Pete Schultz of Brown University, Providence, R.I.  "The heat 
produced by impact was at least several thousand degrees Kelvin 
and at that extreme temperature just about any material begins 
to glow. Essentially, we generated our own incandescent photo 
flash for less than a second."

The flash created by the impact was just one of the visual surprises 
that confronted the Deep Impact team. Preliminary assessment of the 
images and data downlinked from the flyby spacecraft have provided 
an amazing glimpse into the life of a comet.  

"They say a picture can speak a thousand words," said Deep Impact 
Project Manager Rick Grammier of NASA's Jet Propulsion Laboratory, 
Pasadena, Calif. "But when you take a look at some of the ones we 
captured in the early morning hours of July 4, 2005 I think you can 
write a whole encyclopedia."

At a news conference held later on July 4, Deep Impact team members 
displayed a movie depicting the final moments of the impactor's life. 
The final image from the impactor was transmitted from the short-lived 
probe three seconds before it met its fiery end.

"The final image was taken from a distance of about 30 kilometers 
(18.6 miles) from the comet's surface," said Deep Impact Principal 
Investigator Dr. Michael A'Hearn of the University of Maryland, 
College Park. "From that close distance we can resolve features on 
the surface that are less than 4 meters (about 13 feet) across.  When 
I signed on for this mission I wanted to get a close-up look at a comet, 
but this is ridiculous. in a great way." 

The Deep Impact scientists are not the only ones taking a close look at 
their collected data. The mission's flight controller team is analyzing 
the impactor's final hours of flight. When the real-time telemetry came 
in after the impactor's first rocket firing, it showed the impactor 
moving away from the comet's path. 

"It is fair to say we were monitoring the flight path of the impactor 
pretty closely," said Deep Impact navigator Shyam Bhaskaran of JPL. 
"Due to the flight software program, this initial maneuver moved us 
seven kilometers off course. This was not unexpected but at the same 
time not something we hoped to see. But then the second and third 
maneuvers put us right where we wanted to be."

The Deep Impact mission was implemented to provide a glimpse beneath 
the surface of a comet, where material from the solar system's 
formation remains relatively unchanged. Mission scientists hoped the 
project would answer basic questions about how the solar system formed, 
by providing an in-depth picture of the nature and composition of the 
frozen celestial travelers known as comets. 

The University of Maryland is responsible for overall Deep Impact 
mission science, and project management is handled by JPL. The 
spacecraft was built for NASA by Ball Aerospace & Technologies 
Corporation, Boulder, Colo.

For the latest images and information about Deep Impact on the 
Internet, visit:
					
www.nasa.gov/deepimpact 

                         -end-