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damienpaul
2004-Jan-06, 03:35 PM
asides the one between mars and jupiter, is there other asteroid belts, i read somewhere that there was one between neptune and uranus....

Littlemews
2004-Jan-06, 06:09 PM
That was Kelper Belt I guess

damienpaul
2004-Jan-06, 11:29 PM
nah the kuiper belt is further on

TheThorn
2004-Jan-07, 12:34 AM
Originally posted by damienpaul@Jan 6 2004, 03:35 PM
asides the one between mars and jupiter, is there other asteroid belts, i read somewhere that there was one between neptune and uranus....
Between Jupiter and Neptune there are some small objects, called Centaurs. But they look to be Kuiper Belt objects that have been perturbed into smaller orbits. Check out

List of Centaurs and Scattered-Disk Objects (http://cfa-www.harvard.edu/iau/lists/Centaurs.html)

The Scattered Disk objects appear to be KBOs that have been bumped out of the standard orbit. Their orbits are either more highly inclined or more eccentric than classical KBOs, or both. Pluto is a Scattered Disk Object. A lot of them come inside Neptune's orbit at times.

The Centaurs look like scattered disk objects that have been purturbed again by one of the Gas Giants into orbits that stay inside Neptune&#39;s. In that listing, they&#39;re the ones with "a" (semi-major axis) < 30 or so, which puts them inside Neptune. There aren&#39;t a lot of them, so I don&#39;t think anyone would refer to it as a "belt". But I&#39;m not aware of anything else between Neptune and Uranus.

Now here&#39;s an interesting one:

Neptune Trojan (http://www.noao.edu/outreach/press/pr03/pr0302.html)

I wonder if it qualifies as a KBO or a Centaur. ;)

damienpaul
2004-Jan-07, 12:37 AM
thanks for that, i couldn&#39;t think of the name of them - centaurs, i am not sure where i read the neptune-uranus belt.

Say, is it possible for these objects to be captured as moons, and maybe alot of the moons of the gas giants are captured centaurs....

TheThorn
2004-Jan-07, 05:17 AM
Highly likely, IMHO.

gerald coll
2004-Jan-07, 09:40 AM
YOU MAY BE THINKING OF THE "GREEKS & TROJANS "

LOCATED AT THE LA OR LE (SORRY FOR SPELLING) POINTS OF JUPITER.

SEE RICHARD PRESTONS BOOK "FIRST LIGHT".

A GOOD READ AND SOME HISTORY OF THE HALE TELESCOPE.

gerald coll
2004-Jan-07, 09:44 AM
SORRY FOR NOT INSERTING "GRANGE" BEFORE THE WORD POINTIN PREVIOUS REPLY.

THATS INSOMNIA FOR YOU.

TheThorn
2004-Jan-08, 04:06 AM
The link I posted as "Nepture Trojan" was about an object that is in one of Neptune&#39;s Lagrange points, just like Jupiter&#39;s trojan asteroids. It&#39;s the first object found in that relationship to a planet other than Jupiter.

I posted it because I was kind of wondering whether it would be classified as a Kuiper Belt object or a Centaur. The KBOs are "trans neptunian" and the Centaurs are all inside Neptune&#39;s orbit, but here&#39;s this thing just sitting right on the line, sharing Neptune&#39;s orbit. It&#39;s just a curiosity, that&#39;s all.

zephyr46
2004-Jan-22, 02:13 AM
IAU: Minor Planet Center (http://cfa-www.harvard.edu/iau/mpc.html) has daily plots of minor planets in our solar system

Any use of these animations for anything other than your own personal enjoyment is not permitted without thir express permission. ( I asked and they said NO &#33;)

Various Lists and Plots (http://cfa-www.harvard.edu/iau/lists/Lists.html) that are available :)

Armagh Observatory (http://szyzyg.arm.ac.uk/~spm/neo_map.html) has this similar plot, (that I think is better, because it has some names) (I must Thank Bill Allen (http://www.hohmanntransfer.com/news.htm) for that link), however they don&#39;t have the Outer Solar System (http://cfa-www.harvard.edu/iau/lists/OuterPlot.html) or Inner Solar System (http://cfa-www.harvard.edu/iau/lists/InnerPlot.html) :(
But that is pretty much the best overall veiw of the Asteroids Belts and whatnot &#33;
Does that help?

http://szyzyg.arm.ac.uk/~spm/neostorm.png

damienpaul
2004-Jan-23, 11:32 AM
WOW

Just a silly question, what does the colour code mean? And obviously they are still detecting these asteroids?

tycho1981
2004-Jan-23, 11:36 AM
what a mess, never thought that :D

aeolus
2005-May-17, 09:12 PM
Originally posted by damienpaul@Jan 23 2004, 11:32 AM
Just a silly question, what does the colour code mean?
Not silly at all.

Green: Asteroids which do not approach close to the Earth right now.

Yellow: Earth approaching asteroids which have orbits which come close to the Earth but they don&#39;t cross the Earth&#39;s orbit. However, their orbits are close enough to the Earth that they could potentially be perturbed by the influence of the planets and begin to cross the Earth&#39;s orbit in a short time.

Red: These cross the Earth&#39;s orbit and are the most directly identifiable astronomical threat for the near future.

This is all taken from (condensed from) the page that offers the map.

Nereid
2005-May-17, 10:00 PM
The Neptunian Trojan is just that ... so far it&#39;s unique&#33;

There are &#39;Earth Trojans&#39; too, but as the orbits they have around the Lagrange points are rather extended, this is not a good description.

Better is the concept of resonance; all Trojans are in 1:1 resonance orbits, Pluto (and plutinos - there are several) are in 3:2 resonance orbits (with Neptune ... I think; I&#39;m going from memory).

The EKB (Edgeworth-Kuiper Belt - everyone forgets poor old Edgeworth&#33;) is indeed a true &#39;belt&#39;, and possibly a much more massive (and interesting) one than the familiar one (between Mars & Jupiter). It seems the EKB has a rather distinct outer boundary - why? And are all the SDOs &#39;merely&#39; scattered EKB objects? Or perhaps (some) the remnants of older, earlier, distinct belt?

Then there&#39;s the question of the Oort Cloud - how many &#39;belts&#39; does it comprise??

TheThorn
2005-May-18, 02:10 AM
If you find asteroids interesting (as I do), then here are a couple of great links for you:

Gerard Faure (http://www.astrosurf.com/aude/map/us/AstFamilies2004-05-20.htm) has an excellent " DESCRIPTION OF THE SYSTEM OF ASTEROIDS" (although it is a year out of date, and a lot happens in this field in a year.)

Petr Scheirich&#39;s (http://www.canadiancontent.net/en/jd/go?Url=http://sajri.astronomy.cz/asteroidgroups/groups.htm) page has some excellent graphical displays that try to show how these different "families" of asteroids are related. Be sure to check out his animation of the Hildas and Trojans at this link (http://sajri.astronomy.cz/asteroidgroups/hildatroj.gif) - it&#39;s probably the best visual explanation I&#39;ve seen of what an orbital resonance is.

The Hildas especially are interesting - they&#39;re in a 3:2 resonance with Jupiter. All the other resonances with Jupiter (e.g. the 2:1 resonance) are empty. They&#39;re the "Kirkwood gaps". But the 3:2 resonance is packed with these "Hildas", the same way that the 2:3 resonance with Neptune is full of the Plutinos (including Pluto).

All orbital resonances are stable - that is, if an object is in resonance with a larger object, it tends to stay there - so why are certain ones full of objects, and other ones, in the middle of a swarm of asteroids, conspicuous as "Gaps"? Why would Jupiter&#39;s gravity herd asteroids into the 3:2 resonance, but clear them out of the other ones? When I came to understand the answer to that question, (and it&#39;s not that difficult), I came to appreciate some of the intricacies of orbital mechanics. I&#39;d try to explain it here, but I already have a reputation for posts that are long and pedantic . ;)

So Nereid, you mentioned the sharp outer edge of the Edgeworth-Kuiper belt. It is often explained as the farthest away that objects condensed out of the primordal cloud that formed the solar system. However, there is another interesting fact about that edge. It just happens to be exactly at the 2:1 resonance with Neptune.

So, maybe it&#39;s not an "edge", maybe it&#39;s a "gap". And if it exists for the same reason that the Kirkwood gaps exist, it&#39;s a real "hint" as well.

The Oort cloud, now, I&#39;ll leave that for another post <grin>.

eburacum45
2005-May-18, 04:03 PM
The list by Gérard Faure has always fascinated me;
he has listed several asteroid families in the main belt I have never seen anywhere else.
To wit;
Flora;
Phocaea;
Vesta;
Nysa-Hertha
Eunomia
Koronis
Eos
Themis
Hygeia
Griqua
Cybele
Hilda
Thule

I have only heard of the Vesta group before;

Nereid
2005-May-18, 04:33 PM
SDSS results have been used to characterise some of these families (http://www.astro.washington.edu/ivezic/sdssmoc/switch.html).