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B1BLancer
Joined: 11 Jul 2003
Posts: 92
Location: SC |
And this ain't bad, either!
 Thu Jul 07, 2005 3:29 am
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From the Chandra X-Ray Observatory.
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Dan Rockwell
Joined: 10 Dec 2001
Posts: 1988
Location: Stamford, CT, USA |
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Sat Jul 09, 2005 8:38 pm
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quote:
Originally posted by B1BLancer
GEEZ, how did we get from Deep Impact to this?! 
I was wondering the same thing Lancer.
I was hoping that NASA would succeed with this mission and it looks like they did. I for one was curious to find out who was right as to the compositon of comets, especially since one of them could cause us a problem one day. And judging by some of the images, it appears that, at least this comet, is a little bit more than just a dirty snowball and they might have to come up with something much bigger to ram into a rogue comet should one wander a little too close to us for comfort. |
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Dan Rockwell
Joined: 10 Dec 2001
Posts: 1988
Location: Stamford, CT, USA |
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Sat Jul 09, 2005 9:05 pm
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This is interesting.
Posted on Fri, Jul. 08, 2005
Scientists: Debris from smashed comet is fine as talcum powder
ALICIA CHANG
Associated Press
LOS ANGELES - The plume of debris that spilled from the belly of a comet after it collided with a space probe is as fine as talcum powder, suggesting the comet formed gradually, scientists said Friday.
Scientists continued to pore over data gathered when a copper probe from NASA's Deep Impact spacecraft blasted a crater in comet Tempel 1 on July 4 to expose its primordial core.
Comets are the frozen leftover building blocks of the solar system, which formed when a huge cloud of gas and dust collapsed to form the sun and planets about 4.5 billion years ago. Studying comets could provide clues to the birth of the solar system.
Soon after the 820-pound probe hit the surface of Tempel 1, scientists detected evidence of hot water, carbon dioxide and organic substances spewing from the comet. The high-speed collision produced two flashes of light and hurled a plume of fine, powdery dust from the pit of the comet thousands of miles into space.
"This probably means the material in the comet came together very gently," said Michael A'Hearn, an astronomer at the University of Maryland and the mission's principal investigator. "If it melted and resolidified, it would have the strength of solid ice."
Scientists are waiting for the dust from the larger-than-expected debris cloud to settle before they can get their first glimpse at the inside of the comet and determine the size and depth of the crater. They said the crater was larger than house-size and possibly as big as a football stadium.
Comets are believed to be abundant in water and partially responsible for replenishing Earth's oceans after asteroids bombarded the planet during its early years and wiped out its water source.
But astronomers were surprised to find a lack of water vapor after the collision. Preliminary findings by a science instrument aboard a NASA satellite in Earth orbit showed Tempel 1 released about 550 pounds of water per second, similar to the amount before the impact, suggesting the comet contain more dust than ice.
"It's pretty clear that this event did not produce a gusher," said Gary Melnick of the Harvard-Smithsonian Center for Astrophysics.
The findings appear to contradict results by the European Space Agency's XMM-Newton Observatory, which this week found evidence of increased water in the comet's emissions after the impact.
The impactor probe was equipped with a camera and beamed back close-up pictures of the comet before slamming into the surface at a 25-degree angle. The last picture was taken three seconds before the probe was obliterated, revealing crater-like features on the comet's surface.
The collision and aftermath was also observed by the Deep Impact spacecraft which had released the probe on a collision course with Tempel 1.
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On the Net:
Deep Impact mission: http://www.nasa.gov/deepimpact |
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B1BLancer
Joined: 11 Jul 2003
Posts: 92
Location: SC |
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Sun Jul 10, 2005 1:04 am
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quote:
Originally posted by Dan Rockwell
quote:
Originally posted by B1BLancer
GEEZ, how did we get from Deep Impact to this?!
I was wondering the same thing Lancer.
I was hoping that NASA would succeed with this mission and it looks like they did. I for one was curious to find out who was right as to the compositon of comets, especially since one of them could cause us a problem one day. And judging by some of the images, it appears that, at least this comet, is a little bit more than just a dirty snowball and they might have to come up with something much bigger to ram into a rogue comet should one wander a little too close to us for comfort.
What I thought was especially curious was the area of the comet surface that looked dark and very smooth, almost like a solidified lava flow. The fact that the area was uncratered indicates that it is relatively young. Is some sort of layering process at work? I'd be very interested to find out how that was created. |
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Dan Rockwell
Joined: 10 Dec 2001
Posts: 1988
Location: Stamford, CT, USA |
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Mon Jul 18, 2005 2:34 am
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quote:
Originally posted by B1BLancer
What I thought was especially curious was the area of the comet surface that looked dark and very smooth, almost like a solidified lava flow. The fact that the area was uncratered indicates that it is relatively young. Is some sort of layering process at work? I'd be very interested to find out how that was created.
The surface could indicate that either it is a young comet or there is enough of a gravitational field to attract dust particles and other pieces of cosmic debris. |
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Dan Rockwell
Joined: 10 Dec 2001
Posts: 1988
Location: Stamford, CT, USA |
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Mon Jul 18, 2005 2:51 am
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Now this is really interesting. Deep Impact is still operational.
July 18, 2005
The washing machine, the comet and a second spin
By Mark Henderson, Science Correspondent
THE Nasa probe that blasted a chunk out of a comet last month is to be rerouted this week in preparation for a bonus mission to examine a second orbiting comet.
Nasa scientists have confirmed that Deep Impact, which fired a probe the size of a washing machine into the comet Tempel 1 on July 4, survived the encounter with barely a scratch, and has now been given a fresh target. The US space agency has cleared the probe’s controllers to perform a small unscheduled manoeuvre later this week that will send it back towards Earth. When it arrives in 2008, it will be rerouted to another comet, 85P/Boethin, provided Nasa comes up with the necessary funds.
Deep Impact has already excelled in achieving its primary goal — blowing a hole in comet Tempel 1 in a 23,000mph collision and analysing the debris for clues to the origins of the solar system. As comets were formed around the same time as the solar system, about 4.6 billion years ago, details of their composition and structure are expected to yield important insights into how the planets were created.
While Deep Impact’s impactor module was destroyed in the blast as expected — it was vaporised as the comet ran it over — scientists had also anticipated that the main section of the ship would be seriously damaged as it flew through the debris of Tempel 1’s tail.
However, tests conducted since the impact have shown that the probe continues to work perfectly. Its optical cameras and solar panels are intact, the craft’s communication antenna is fully operational, and it is carrying plenty of fuel.
As a result, the mission team have successfully lobbied Nasa to allow them to send the spacecraft elsewhere. Although it will not be able to repeat the feat of July 4, as it carried only one impactor bullet, its sophisticated cameras and instruments will be able to give astronomers a close look at the nucleus of another comet.
Michael A’Hearn, who is leading the project, said that astronomers have selected 85P/Boethin as the most appropriate comet to visit next. It was spotted in 1975 by Leo Boethin, an amateur astronomer, and orbits the Sun every 11 years.
http://www.timesonline.co.uk/article/0,,3-1698377,00.html |
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B1BLancer
Joined: 11 Jul 2003
Posts: 92
Location: SC |
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Mon Jul 18, 2005 3:05 am
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quote:
Originally posted by Dan Rockwell
The surface could indicate that either it is a young comet or there is enough of a gravitational field to attract dust particles and other pieces of cosmic debris.
I'm not sure there's such a thing as a young comet. I think pretty much all objects in the solar system were formed around the same time frame. The really weird thing is that the rest of the visible surface looks as you would expect, which is rugged and cratered. Then, you see this one really smooth, dark area that sticks out like a sore thumb. Strange. |
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B1BLancer
Joined: 11 Jul 2003
Posts: 92
Location: SC |
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Mon Jul 18, 2005 3:07 am
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quote:
Originally posted by Dan Rockwell
Now this is really interesting. Deep Impact is still operational.
COOL!! That's great to hear. I had wondered what the mission plan called for if the spacecraft survived the encounter. |
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