Posted on 03/14/2007 8:41:56 PM PDT by NormsRevenge
PARIS (AFP) - Astronomers have pieced together the remnants of a mighty collision that smashed apart a planet-sized rock in the Kuiper Belt, on the far-flung fringes of the Solar System.
First identified in the 1950s by Dutch-US skygazer Gerard Kuiper, the disk-shaped belt is believed to be populated by tens of thousands of icy bodies, encircling the Sun beyond the orbit of Neptune.
A team led by Michael Brown of the California Institute of Technology (Caltech) took a close look at the belt's third largest object, 2003 EL61.
Nicknamed "Santa" because the team spotted it at Christmas-time, 2003 EL61 is a grey rock so big that it is a contender for the new category of a Solar System "dwarf planet."
Brown describes Santa as "one of the strangest objects in the Solar System," likening its shape to a cigar or an American football that has too little air in it and been stepped on.
Flanked by two moonlets, 2003 EL61 measures some 1,500 kilometers (950 miles) across, tumbling over and over at a prodigious rate and pursuing a weird egg-shaped orbit inclined at nearly 30 degrees to the plane at which almost all of the Solar System's objects travel.
Brown's team found five other rocks, measuring between 10 and 400 kilometers (six and 250 miles) across, that they believe were smashed away from 2003 EL61 in the distant past.
The cluster shares the same colour and the light they reflect has a signature that suggests they are covered with surface water ice. The paper is published on Thursday in the weekly British journal Nature.
The Kuiper Belt and the asteroid belt, which is located in the gap between Mars and Jupiter, are believed to be rubble left over from the building of the Solar System.
Astronomers have already identified 35 "collisional families" -- clusters formed when their parent rock is whacked -- in the asteroid belt.
But this is the first time something similar has been spotted in the Kuiper Belt, and the discovery could shed light on the dynamics that shaped the early Solar System and the surface of Kuiper Belt objects themselves.
The chance of the collision occurring that formed the Santa family "is only about 1 in 2,000," estimates Alessandro Morbidelli of France's Observatoire de la Cote d'Azur in a commentary, also published by Nature.
"We have many indications that the Kuiper Belt was initially much more massive than it is today," says Morbidelli.
"Presumably, therefore, the collision must have happened in the distant past, when the belt was far more crowded with large objects."
Brown is one of the leading authorities on the Kuiper Belt, a region also inhabited by Pluto.
His discovery of a big Kuiper Belt object, 2003 UB303 (since renamed 2003 Eris), sparked a fierce debate about the status of planets, leading to Pluto's relegation last year to the status of "dwarf planet" by International Astronomical Union (IAU).
Artist's rendition released by NASA shows an asteroid belt in orbit around a star. - Astronomers have pieced together the remnants of a mighty collision that smashed apart a planet-sized rock in the Kuiper Belt, on the far-flung fringes of the Solar System.(AFP/NASA-HO/File)
2003 EL61
the strangest known object in the Kuiper belt
http://www.gps.caltech.edu/~mbrown/2003EL61/
I'm going to need braces...
I'm always impressed and appreciative of your posts NR.
My pleasure. Thanks for your kind remarks.
thought for sure someone would have posted a dwarf santa by now..
Oh well.. ;-)
battlegearboat: I'm always impressed and appreciative of your posts NR.Me too.
If you remove the Kuiper Belt from a dwarf Santa, do his pants fall down?
Questioning Dwarfs [hi-ho, hi-ho, he means a KBO]
Astrobiology Magazine | March 7, 2007 | Michael Brown et al
Posted on 03/12/2007 12:00:23 AM EDT by SunkenCiv
http://www.freerepublic.com/focus/f-chat/1799308/posts
a "name" tag from the same page linked by NormsRevenge above:
http://www.gps.caltech.edu/~mbrown/2003EL61/#impact
"One of the interesting predictions of this hypothesis is that the debris from the collision, from which the satellites formed, should have been composed predominantly of ice, rather than rock. The satellites themselves, then, should be almost purely ice... While the odd characteristics of 2003 EL61 and its moons initially led us to the hypothesis of a giant impact, the smoking gun came when we found the other icy debris left over from the collision in orbits similar to 2003 EL61 itself... Most of the other Kuiper belt objects have much more complex surfaces that are difficult to understand, but 2003 EL61, its satellites, and these five new objects all appeared unique. While trying to understand why these we different it suddenly became glaringly obvious that all of these objects were on very similar orbits, and that if you traced those orbits back in time you would be able to connect them to a single location where they were once part of a larger body (this is an oversimplification, but gets the main point)."
Here's an X-Planets topic, but it's also on the Catastrophism list.
update, using an existing topic.
Mike Brown’s Planets (blog)
Nervous gyrations
Saturday, May 3, 2008
http://www.mikebrownsplanets.com/2008/05/nervous-gyrations.html
[snip] On May 11th and then four other days over the following two week period, the [Hubble Space] telescope will come around the earth, swing towards Santa, and snap a quartet of pictures to help us determine precisely where the small satellite (aka Blitzen) is. [end]
2003 EL61 (Mike Brown’s page about it)
http://web.gps.caltech.edu/~mbrown/2003EL61/
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