NASA/JPL-Caltech | Asteroid Belt | An illustration of the asteroid belt. A team of researchers has found that many of the asteroids that populate the asteroid belt between Mars and Jupiter were actually once former comets.
Posted on 07/16/2009 7:32:16 PM PDT by SunkenCiv
Many of the primitive bodies wandering the asteroid belt between Mars and Jupiter are former comets, tossed out of orbit by a brutal ballet between the giant outer planets, said a team of astrophysicists. A commonly accepted theory is that the asteroid belt is the rubble left over from a "proto-planetary disk," the dense ring of gas that surrounds a new-born star. But the orbiting rocks have long been a source of deep curiosity. They are remarkably varied, ranging from mixtures of ice and rock to igneous rocks, which implies they have jumbled origins. The answer to the mystery, according to a study published by the British journal Nature on Wednesday, is that a "significant fraction" of the asteroid population in fact comprises ex-comets... Researchers in France and the United States ran a mathematical model of the development of the early solar system, when the planets were accreting from clustering masses of dust and gas. According to this model, the nascent giant planets -- Jupiter, Saturn, Uranus and Neptune -- orbited at this time in a pretty compact configuration, between five and 15 astronomical units (AUs) from the Sun... As the giants became bigger and bigger, their orbits became unstable. Eventually, after around 600 million years, Uranus and Neptune were kicked out by gravitational jousting... If the model is right, it implies that the difference between the most primitive asteroids and comets is even slimmer than thought.
(Excerpt) Read more at dsc.discovery.com ...
NASA/JPL-Caltech | Asteroid Belt | An illustration of the asteroid belt. A team of researchers has found that many of the asteroids that populate the asteroid belt between Mars and Jupiter were actually once former comets.
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Sleep tight and hope a comet tossed out of orbit by a brutal ballet between the giant outer planets doesn't hit your house at 40K miles per hour before you wake!
Wouldn’t this mean that the asteroid belt is loaded with ice, and could therefore be the basis for sustaining life and generating fuel, making mining the asteroids far more of a practical possibility?
Gina Haley meets The Comets
“Asteroid Belt Loaded with Four Comets”
Gee, I hope he can make it through security checkpoints.....
Lets go!!
We don’t need this future slave world
“Eventually, after around 600 million years...”
That’s the timeframe for getting the ‘0bama National Debt’ paid off, isn’t it? ;)
Heh... this coin-related story is probably postworthy, but I’m going to bed. It’s amusing.
http://www.5tjt.com/news/read.asp?Id=4588
Whoa... his daughter?
Thanks. At least it would be quick.
Did Jupiter Bully Other Planets in Sibling Rivalry?One possible explanation, discussed in Thursday's issue of the journal Nature, is that Uranus and Neptune formed much closer to the center of the action than their current positions might indicate. In this scheme, Jupiter and Saturn were bullies of a protoplanetary playground, shoving the other two future giants out of the way.
by Robert Roy Britt
8 December 1999Jupiter gave birth to Uranus and NeptuneNot too long ago, scientists regarded the orbits that the planets circle our Sun as being the ones they were born in. Now they are realising that this is not the case. Uranus and Neptune may have migrated outwards and Jupiter may have come in from the outer cold. Scientists have always been slightly puzzled by the positions of Uranus and Neptune because in their present locations it would have taken longer than the age of the Solar System for them to form. Scientists from Queen's University suggest that the four giant planets started out as rocky cores in the Jupiter-Saturn region, and that the cores of Uranus and Neptune were tossed out by Jupiter's and Saturn's gravity.
by Dr David Whitehouse
8 December, 1999Jupiter's Composition Throws Planet-formation Theories into DisarrayExamining four-year-old data, researchers have found significantly elevated levels of argon, krypton and xenon in Jupiter's atmosphere that may force a rethinking of theories about how the planet, and possibly the entire solar system, formed. Prevailing theories of planetary formation hold that the sun gathered itself together in the center of a pancake-shaped disk of gas and dust, then the planets begin to take shape by cleaning up the leftovers. In Jupiter's current orbit, 5 astronomical units from the sun, temperatures are too warm for the planetesimals to have trapped the noble gases. Only in the Kuiper belt -- a frigid region of the solar system more than 40 AU from the sun -- could planetesimals have trapped argon, krypton and xenon.
by Robert Roy Britt
Nov 17 1999
While lead researcher Tobias Owen does not put much stock in the idea that Jupiter might have migrated inward to its present position, other scientists on the team say the idea merits consideration. Owen expects the probes will find similarly high levels of noble gases in Saturn, Uranus and Neptune. Hints of these gases have even been found in the thick atmosphere of Venus, another planet now begging more study.
Nature of comets reconsideredThe long-held perspective that comets are pristine remnants from the formation of the solar system has evolved from the prevailing views of 30 years ago, finds planetary scientist Dr. S. Alan Stern in a paper published in the journal Nature... The first evolutionary process to be recognized as affecting comets during their long storage was radiation damage, followed by the discovery that sandblasting from dust grains in the interstellar medium plays an important role. Next, researchers theorized that comets in the Oort cloud are heated to scientifically significant temperatures by passing stars and supernovae, says Stern. More recently, researchers are finding that comets in the Kuiper Belt are heavily damaged by collisions... The classical view that comets do not evolve while they are stored far from the sun in the Oort cloud and Kuiper Belt began to change as far back as the 1970s, but the pace of discoveries about the way comets evolve picked up considerably in the 1980s and 1990s.
Southwest Research Institute
August 8, 2003
The postulated Kuiper Belt may be. Ice goes straight to vapor in vacuum, but in sufficient quantity could hold together through its own mass, probably would also need a coating of dust and debris.
his youngest daughter, Gina Haley
[after some more thought]
Maybe, to an *optimist*. ;’)
Note: this topic is from 07/16/2009. Adding, not pinging.
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