Posted on 07/04/2005 4:30:19 AM PDT by Man50D
PASADENA, Calif. - A space probe hit its comet target late Sunday in a NASA-directed, Hollywood-style mission that scientists hope will reveal clues to how the solar system formed. It was the first time a spacecraft had ever touched the surface of a comet, igniting brief Independence Day weekend fireworks in space.
The successful strike 83 million miles away from Earth occurred at 10:52 p.m. PDT, according to mission control at NASA's Jet Propulsion Laboratory in Pasadena. Scientists on the mission — called Deep Impact, like the movie — erupted in applause and exchanged hugs.
"A lot of people said we couldn't do this or wouldn't be able to pull it off," project manager Rick Grammier said later at a predawn Monday news conference. "It happened like clockwork and I think that's something to be proud of on America's birthday."
The cosmic smash-up did not significantly alter the comet's orbit around the sun and NASA said the experiment doesn't pose any danger to Earth.
An image by the mothership, which had released the barrel-sized "impactor" probe on its suicide mission 24 hours earlier, showed a bright spot in the lower section of the comet where the collision occurred. A cloud of debris was hurled into space. When the dust settles, scientists hope to peek inside the comet's frozen core — a composite of ice and rock left over from the early solar system.
"We hit it just exactly where we wanted to," co-investigator Don Yeomans said.
Among stargazers awaiting the event across the country were more than 10,000 people at Hawaii's Waikiki Beach who saw the impact on a giant movie screen. Some skywatchers said they even spotted a red streak across the southwestern sky that lasted several seconds.
"It's almost like one of those science fiction movies," said Steve Lin, a Honolulu physician as his 7-year old son, Robi, zipped around his beach blanket.
Bob Joseph, faculty chair at the University of Hawaii Institute for Astronomy, commended NASA scientists. "Nobody has ever done an experiment like this ever in the history of the world," he said.
The impact caused the comet — a pickle-shaped body half the size of Manhattan — to shine six times brighter than normal, said Michael A'Hearn, principal investigator of the $333 million project.
Scientists had compared the impactor probe's journey toward the path of the Tempel 1 comet as similar to standing in the middle of a road and being hit by a semi-truck roaring at 23,000 mph. They have estimated the crater may range in size from a large house to a football stadium with a depth of two to 14 stories deep.
A direct hit by the 820-pound copper probe was a challenge because NASA's Jet Propulsion Laboratory no longer controlled it once it was released from the spacecraft. Even so, the odds favored success based on previous testing.
After its release a day earlier, the battery-powered probe tumbled in free flight toward the comet and flew on its own without human help during the critical two hours before the crash, firing its thrusters to get a perfect aim of the comet nucleus.
The probe's camera temporarily blacked out twice, probably from being sandblasted by comet debris, Yeomans said. Still, it took pictures right up to the final moments, revealing crater-like features. The last image was taken three seconds before impact.
The carefully orchestrated crash gave off energy equivalent to exploding nearly 5 tons of dynamite.
The mothership had a front-row seat to the comet strike 5,000 miles away. NASA's fleet of space telescopes, including the Hubble Space Telescope, Chandra X-ray Observatory and Spitzer Space Telescope, and dozens of ground observatories also viewed the impact.
Soon after the probe's crash on the comet's sunlit side, the mothership prepared to approach Tempel 1 to peer into the crater site and send more data back to Earth. The spacecraft was to fly within 310 miles of the comet before activating its dust shields to protect itself from a blizzard of debris.
Comets are frozen balls of dirty ice, rock and dust that orbit the sun. A giant cloud of gas and dust collapsed to create the sun and planets about 4.5 billion years ago and comets formed from the leftover building blocks of the solar system.
As comets circle the sun, their surfaces heat up and change so that only their frozen interiors possess original space material. Scientists hope to analyze images of these primordial ingredients jarred loose by the impact to give new insight into how the sun and planets formed.
Deep Impact launched Jan. 12 from Cape Canaveral, Fla., on a six-month, 268 million-mile voyage. In what scientists say is a coincidence, the spacecraft shares the same name as the 1998 movie about a comet hurtling toward Earth.
The 1,300-pound spacecraft snapped its first photo of Tempel 1 from 40 million miles away in April. Last month, still 20 million miles away, scientists saw the comet's solid core for the first time.
No other space mission had come this close to a comet. In 2004, NASA's Stardust craft flew within 147 miles of Comet Wild 2 en route back to Earth carrying interstellar dust samples.
You can run...but you just can't hide...heh heh heh...
Ah, the practical applications of antibalistic trajectory physics.
We watched JPL do its thing on NASA channel over five hours ago. Are you sure no one else has posted this news?
Cool photos.
Can anybody post them?
I did a title search by date and no match was returned. Also the time ticker on the page for this story showed it had been on the Yahoo website for eight minutes when I posted it to Freep.
And the purpose of this $333 Million experiment was......?
To see how fast a luddite goes from zero to whine in 60 seconds
Practice?
I'm just surprised another space buff didn't post the news earlier.
I tried to find the photos of the explosion on the comet when the probe strike occurred, but none at Google.
Maybe I'll try Yahoo.
To continue to train a pool of scientists whose brains we can pick for anti-balistic missile trajectory physics and computer programming of same.
If you want the scientists there when you need them really badly, you have to give them toys to play with until they are really badly needed, so they'll be up on their game when push comes to shove.
Besides, blowing up things in space is fun.
The pursuit of knowledge, and well worth it.
Demonstrating to the Chinese and the EU, good ole American know-how.
Cool! Thanks for the Link!
Best answer I've heard!
The same crowd which said our ballistic missile defense system wouldn't work, perhaps?
This was a proof-of-concept test. This shows we can hit a comet or asteroid with a nuclear warhead if need be.
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