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Spitzer telescope sees long, violent history for planet-building
Monterey Herald ^ | 10/18/04 | Robert Jablon - AP

Posted on 10/18/2004 8:07:17 PM PDT by NormsRevenge

LOS ANGELES - The Spitzer telescope's examination of hundreds of stars has found evidence that the times it takes to form an Earth-sized planet may last hundreds instead of tens of millions of years.

The telescope revealed dust rings around nearby stars that couldn't have survived long unless violent collisions between gigantic chunks of rock were replenishing them, scientists said during a press conference Monday at NASA's Jet Propulsion Laboratory in Pasadena.

Scientists have long believed that planets are formed when the dust in a disc-like formation around a young star begins to clump. Some of the clumps eventually grow to the size of mountains and these smash into each other, where some of the matter is absorbed to create a larger embryonic planetoid.

These, in turn, collide with each other, creating more dust and rocky chunks that keep smashing into each other. In some theories, this brutal stage of planet growth lasts perhaps 10 million years or so - an eye blink in astronomical terms. Then there is a long, steady, quieter cleanup period in which the unused dust dissipates.

Scientists found something interesting, however, when NASA's Spitzer Space Telescope turned its infrared eye on the stars.

Of 266 stars observed, 71 had dusty discs, but instead of having faded, some discs were big and bright even though their stars were 100 million to 200 million years old.

The dust, detected via its heat signature because it is warmed by the star, would have dissipated in that time unless big, recent collisions were replenishing it, researchers said.

The collisions appear to involve a planet colliding with something 10 to 200 miles in diameter.

"Now, we will have to rewrite the textbooks ... the disks can last much longer than previously thought and can be replenished," said Jonathan Gardner, Spitzer program scientist in Washington, D.C.

The latest findings provide more clues to how motes of dust become a world. The process may be how our own solar system was created and also could be another indicator that Earth-sized planets are common in the universe, researchers said.

There is a "clear link" between formation of planets in our solar system and those around other stars, said Scott Kenyon, a senior astrophysicist at the Smithsonian Astrophysical Observatory in Cambridge, Mass., who studies the formation of planetary systems.

"When we look out into space, we see our own history," Kenyon said.

The fact that other stars show the dust rings "probably means planets are forming around all these stars," he added.

Spitzer was launched Aug. 25, 2003, as the fourth member of NASA's Great Observatories program, following the Hubble Space Telescope, the Chandra X-ray Observatory and the Compton Gamma Ray Observatory, which is no longer in orbit.

ON THE NET

http://www.spitzer.caltech.edu/Media/041018telecon/


TOPICS: Culture/Society; Government; US: California
KEYWORDS: catastrophism; history; nasa; planetbuilding; spacetelescope; spitzer; spitzertelescope; telescope; violent; xplanets

1 posted on 10/18/2004 8:07:18 PM PDT by NormsRevenge
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To: PatrickHenry

Deploy the ping list!


2 posted on 10/18/2004 8:14:22 PM PDT by longshadow
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To: NormsRevenge
The process may be how our own solar system was created and also could be another indicator that Earth-sized planets are common in the universe, researchers said.

The negation of this sentence is also a reasonable interpretation of the results described in the article: The process may be unlike how our own solar system was created and also could be another indicator that Earth-sized planets are comparatively rare in the universe.

Since approximately a quarter of the observations found unexpectedly long-lived dust rings, this suggests that the distribution of material agglomeration with time is greater than previously had been thought. This does not seem all that surprising.

3 posted on 10/18/2004 8:27:52 PM PDT by Faraday
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To: NormsRevenge
The process may be how our own solar system was created and also could be another indicator that Earth-sized planets are common in the universe, researchers said.

The negation of this sentence is also a reasonable interpretation of the results described in the article: The process may be unlike how our own solar system was created and also could be another indicator that Earth-sized planets are comparatively rare in the universe.

Since approximately a quarter of the observations found unexpectedly long-lived dust rings, this suggests that the distribution of material agglomeration with time is greater than previously had been thought. This does not seem all that surprising.

4 posted on 10/18/2004 8:28:40 PM PDT by Faraday
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To: Faraday

Oops. Must be a distortion in the Matrix.


5 posted on 10/18/2004 8:30:04 PM PDT by Faraday
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To: NormsRevenge

Its all George W. Bush's fault too.....


6 posted on 10/18/2004 9:24:43 PM PDT by festus (Whats the frequency Kenneth ?)
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To: festus

Gee. We've talked it to death. God said, "Let there be . . ." and awesome forces were unleashed . . . Sorry,
that's the Twinkie Digest way of explaining it without having to talk about quarks.


7 posted on 10/18/2004 9:47:48 PM PDT by Twinkie
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To: VadeRetro; jennyp; Junior; longshadow; RadioAstronomer; Physicist; LogicWings; Doctor Stochastic; ..
Science list Ping! This is an elite subset of the Evolution list.
See the list's description in my freeper homepage. Then FReepmail me to be added or dropped.
8 posted on 10/19/2004 3:31:40 AM PDT by PatrickHenry (Hic amor, haec patria est.)
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To: NormsRevenge

Planets are destroyed with a bit of violence as well....
9 posted on 10/19/2004 3:36:32 AM PDT by RandallFlagg (I FINALLY updated my FReeper page! Click on my name and see how you can help our President!)
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To: NormsRevenge

or maybe someone's blowing up the planets, recreating the dust rings.


10 posted on 10/19/2004 3:37:37 AM PDT by Gothmog (The 2004 election won't be about what one did in the military, but on how one would use it)
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To: PatrickHenry

Thanks for the ping!


11 posted on 10/19/2004 11:34:49 AM PDT by Alamo-Girl
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To: LogicWings
What would our own asteroid belt look like from a few thousand light years distance? It would seem pretty fuzzy. Also demonstrates that such structures can be self maintaining.

I'm not sure this article really says anything. Maybe some solar systems are such that they never form planets. Wait another 200 million years and they will still be in the same state.

I'm not convinced this says anything about the development of planets at all.

12 posted on 10/19/2004 6:38:45 PM PDT by LogicWings
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To: LogicWings
What would our own asteroid belt look like from a few thousand light years distance?

Invisible

I'm not sure this article really says anything. Maybe some solar systems are such that they never form planets. Wait another 200 million years and they will still be in the same state.

So long as the ring is outside the Roche limit, gravity alone can condense it into a planet or moon depending on the parent body.

13 posted on 10/20/2004 7:46:01 AM PDT by RadioAstronomer
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To: 75thOVI; agrace; aimhigh; Alice in Wonderland; AndrewC; aragorn; aristotleman; Avoiding_Sulla; ...
Note: this topic is from 10/18/2004. Thanks NormsRevenge.



14 posted on 10/24/2012 5:06:44 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/)
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To: KevinDavis; annie laurie; Knitting A Conundrum; Viking2002; Ernest_at_the_Beach; Mmogamer; ...
Note: this topic is from 10/18/2004. Thanks NormsRevenge.
 
X-Planets
· join · view topics · view or post blog · bookmark · post new topic · subscribe ·
Google news searches: exoplanet · exosolar · extrasolar ·

15 posted on 10/24/2012 5:09:57 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/)
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