In this artist's rendering, the aging star IRC+10216 vaporizes a belt of comet-like objects in its vicinity. Image courtesy of the Smithsonian Astrophysical Observatory
Posted on 03/15/2006 7:51:58 AM PST by SunkenCiv
IRC+10216, also known as CW Leonis, was once a well-behaved main-sequence star as our own Sun is now... When astronomers turned the satellite toward IRC+10216 they discovered a substantial cloud of water vapor about 100 AU across. ("AU" --short for Astronomical Unit-- is a unit of length used by astronomers. One AU equals the mean distance between Earth and the Sun.) "There must be about four Earth-masses of frozen water around IRC+10216 to produce the vapor cloud we see," says Melnick. The water vapor probably does not come from the vaporization of oceans on an Earth-like planet, because there wouldn't be enough water on such a planet to supply the cloud. Instead, the researchers speculate, the vapor cloud might come from a swarm of several hundred billion comets orbiting 75 AU to 300 AU from the star... The discovery of water vapor around IRC+10216 is reported in the July 12th edition of the journal Nature. In addition to Melnick, Neufeld and Ford, the other co-authors are Dr. David Hollenbach of NASA's Ames Research Center and Dr. Matthew Ashby of the Harvard-Smithsonian Center for Astrophysics.
(Excerpt) Read more at science.nasa.gov ...
In this artist's rendering, the aging star IRC+10216 vaporizes a belt of comet-like objects in its vicinity. Image courtesy of the Smithsonian Astrophysical Observatory
PING
Carbon clue implies comets orbit other starsCarbon ions have been seen for the first time in a comet's tail by US scientists. The finding suggests that comets, so far seen only in our own Solar System, might well orbit other stars. This conclusion stems from the fact that similar charged particles have been measured in the light from a nearby star, Beta Pictoris, which is surrounded by a dusty disk... The new discovery represents the first strong evidence that dust contributes to a comet's plasma tail, rather than only evaporating ices. Comet Kudo-Fujikawa was discovered in December 2002 and is thought to orbit the Sun once every 50,000 to 100,000 years... The comet passed five times closer to the Sun than the Earth does, experiencing 25 times the radiation. A spectrometer on SOHO allowed the team to deduce which ions were present in the comet... The tail contained about 700 million kilograms of carbon ions. The sheer mass of carbon ions - equivalent to 25 per cent of the comet's water - took the researchers by surprise. It meant the source of the ions could not be the usual suspect, carbon monoxide ice, as this made up less than 10 per cent of the comet relative to water... Some scientists have suggested that the chemical building blocks of life may have arrived on Earth on impacting comets. Povich says their study does not directly address that question, but adds "it is reassuring to see these materials reappearing".
by Maggie McKee
15:15 12 December 03
'Shocking' Experiment Reveals How Asteroids ExplodeWhen watery asteroids are shocked at the surface by an impact -- something that happens to all space rocks several times during their histories -- dust explodes into space. When a dry asteroid is hit by a another rock, not much happens, dustwise. "As a result of these differences in shock response, watery material would become the predominant kind of dust particles produced by mutual collisions of asteroids, Tomeoka said, adding that larger watery fragments would not be abundant.
Thu May 1, 9:49 AM ET
by Robert Roy Britt
Strange Comet Unlike Anything Known[D]ozens of photos show no small craters on Wild 2, only the large craters that are presumably billions of years old... Brownlee is also intrigued by the utter lack of similarities between Wild 2 and Phoebe, a fairly small moon of Saturn recently imaged up close by the Cassini spacecraft. Phoebe is thought to be a captured object, having originated -- like Wild 2 -- beyond Neptune. But Phoebe's gently sloping craters, which are riddled with boulders, resemble those seen on asteroids. And Phoebe has many small craters embedded in larger, older craters.
by Robert Roy Britt
Cool -- they found the Oort Cloud.
Very likely. Got to wonder how they could see it so easily and can hardly see our own. Maybe we're too close to ours.
There isn't one around ours. :')
and oldie:
Gravitational anomalies: An invisible hand?
From The Economist print edition | Aug 19th 2004
Posted on 08/21/2004 4:31:57 AM EDT by ScuzzyTerminator
http://www.freerepublic.com/focus/f-news/1196132/posts
Bump
I thought this was about Farrah Fawcett. Sorry.
That remark *drained* all the joy out of this exciting topic.
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