Printable Version of Topic

Click here to view this topic in its original format

Unmanned Spaceflight.com _ Pluto / KBO _ 2003 EL61

Posted by: SigurRosFan Mar 14 2007, 09:14 PM

----------
Mike Brown ... and his team discovered that five small Kuiper belt objects were travelling in similar orbits to 2003 EL61, the third-largest KBO ever found. The discovery hinted that the five pieces are fragments that split off after an ancient collision.
----------

- http://space.newscientist.com/article/mg19325955.200

Posted by: alan Mar 14 2007, 11:02 PM

QUOTE
For now, the EL61 family tree includes: 1999 OY3, 1995 SM55, 1996 TO66, 2002 TX300, 2003 OP32, and the moons of 2003 EL61. But Barkume hopes to examine many more family candidates in the coming months.

http://skytonight.com/news/home/4398671.html

I wouldn't call 2002 TX300 small, its the tenth brightest (absolute magnitude) in the Kuiper belt.

Posted by: SFJCody Mar 15 2007, 07:59 AM

2003 EL61 would make an excellent target for the next KBO mission. It's a pity it's not in the right place for a Uranus or Neptune GA.

Posted by: hendric Mar 15 2007, 05:25 PM

In related news, from Distant EKOs:

http://www.boulder.swri.edu/ekonews/issues/past/n051/html/index.html

Transneptunian Object 2003 UB313 as a Source of Comets

A.S. Guliev1

1 Shemakha Astrophysical Observatory, National Academy of Sciences of Azerbaijan, Shemakha, 373243, Azerbaijan

The possibility of interrelation between long-period comets and 2003 UB313, a recently discovered large Kuiper Belt body, is investigated. For this purpose, 78 objects crossing the plane of motion of this body at distances from 37.8 to 97.6 AU have been selected from 860 long-period comets. The overpopulation of comets with this characteristic is also considered. The plane of motion of 2003 UB313 is compared with the orbital planes of other objects in number of comet crossings in the specified distance interval or in some parts of it. A statistically significant overpopulation of elliptic and intermediate comets with the corresponding orbital nodes has been established. Recently discovered and absolutely faint comets show the best effect in this sense. The same is also true for comets with osculating eccentricities e < 1. A similar result is also obtained for comets with ``original'' a1 > 0.010000. It is hypothesized that the 2003 UB313 family is present among the 78 comets. Four of them have aphelion distances from 37.8 to 97.6 AU. An ellipticity is traceable in the distribution of some of the 78 distant nodes. This may be considered as a further argument for the suggested hypothesis. Generally, the body 2003 UB313 may be assumed to play a prominent role in injecting observable comets from the transneptunian region.

Published in: Solar System Research, 41, 46 (2007 February)

[Astronomicheskii Vestnik, 41, 51]

Posted by: Superstring Mar 15 2007, 09:08 PM

Looking at the recent articles on the subject...is there any reason why they conclude the impact took place in ancient history? I ask because EL61 is a bright object covered in fresh crystalline ice (which can only last for 10 million years in that part of the solar system before turning amorphous). I had assumed this was due to the said impact that created its satellites and those other objects.

To me the presence of such fresh crystalline ice on most of its surface leaves two options: a)the impact that created the satellites and orbital family took place in the past 10 million years, or b)the impact took place long ago and triggered enough heat in the core for cryovolcanism which continues to this day.

I'm trying to rule out one or the other...anyone know if the ice on these smaller objects is crystalline? That would strongly suggest a recent impact. I know the brighter satellites has crystalline ice, but that doesn't necessarily rule out cryovolcanism, which could spray material onto its surface.

Posted by: SigurRosFan Sep 5 2007, 02:19 PM

1 billion years is the minimum age of the 2003 EL61 system.

- http://arxiv.org/abs/0709.0328 (D. Ragozzine, M. E. Brown)

Posted by: nprev Sep 5 2007, 09:18 PM

Nice teaser in that abstract about fresh surfaces being incompatible with the derived age of the 2003EL61 group. Is he trying to imply active cryovolcanic processes on the larger KBOs, perhaps...? huh.gif

Posted by: stevesliva Sep 5 2007, 09:56 PM

QUOTE (nprev @ Sep 5 2007, 05:18 PM) *
Is he trying to imply active cryovolcanic processes on the larger KBOs, perhaps...? huh.gif

Nope, foliage. wink.gif

Posted by: Gsnorgathon Sep 6 2007, 02:47 AM

If its perihelion (http://en.wikipedia.org/wiki/2003_EL61) is sufficiently close, might not the crystalline ice just be due to sublimation of surface ices that then freeze out later? I'm imagining a process similar to Pluto's, where its atmosphere is re-created and then freezes out on every orbit.

I guess part the trick would be to wait until perihelion or thereabouts, and see if an atmosphere develops, and if the ice remaining on the surface is crystalline or amorphous. If amorphous, then no recent cryovolcanism. If crystalline, then maybe cryovolcanism, or maybe just excess unsublimated ice.

Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)