Space rocks group name?

In article ,
Jonathan Brimsfield wrote:
I am looking for the name of the area or group from which Jupiter, et al
can nudge space rocks towards earth. I am *NOT* referring to the Asteroid
Belt between Mars and Jupiter.

Unfortunately, that *is* the group in question. There are zones within
the asteroid belt where resonances with Jupiter make orbits evolve very
rapidly and chaotically. When an asteroid's orbit, evolving very slowly
by more subtle processes, enters one of those zones, it can be driven into
the inner solar system quite quickly. If this process continues, the low
end of the orbit will soon be driven low enough to intersect the Sun...
but if the asteroid makes a close encounter with one of the inner planets
first, that can kick it out of the resonance, leaving a reasonably stable
orbit which is wholly or partly in the inner solar system. And that in
turn gives it time to have some chance of actually hitting one of the
inner planets.
--
MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer
pointing, 10 Sept; first science, early Oct; all well. |

(Jonathan Brimsfield) writes:

I am looking for the name of the area or group from which Jupiter, et al
can nudge space rocks towards earth. I am *NOT* referring to the Asteroid
Belt between Mars and Jupiter. I am also *NOT* referring to the Oort
Cloud or the Kuiper Belt.

I think you are confusing several different things together.
The main source of asteroids is the asteroid belt. There may be a few
miscellaneous leftovers from the dissipation of the protoplanetary disk
and well as the corpses of dead comets, but basically, most asteroids
are from the main belt --- and specifically, from the Kirkwood resonance
regions of the main belt, whose orbital periods are related to Jupiter's
by small integer ratios, e.g., 2:1, 3:1, 3:2, etc. There are no other
major sources of small objects in the solar system except the asteroid belt,
the Kuiper belt of icy objects thrown out of the protoplanetary disk by the
giant planets, and the Oort cloud.


I recall reading that this belt of rocks intersects orbits of some
planets annually? Not sure about this bit...

Again, it sounds like you have confused the trails of dust particles
left by comets along their orbits with some sort of "belt of rocks."


-- Gordon D. Pusch

perl -e '$_ = \n"; s/NO\.//; s/SPAM\.//; print;'

Henry Spencer wrote:
In article ,
Jonathan Brimsfield wrote:

I am looking for the name of the area or group from which Jupiter, et al
can nudge space rocks towards earth. I am *NOT* referring to the Asteroid
Belt between Mars and Jupiter.


Unfortunately, that *is* the group in question. There are zones within
the asteroid belt where resonances with Jupiter make orbits evolve very
rapidly and chaotically. When an asteroid's orbit, evolving very slowly
by more subtle processes, enters one of those zones,

The zones you speak of are the Kirkwood gaps?

it can be driven into
the inner solar system quite quickly. If this process continues, the low
end of the orbit will soon be driven low enough to intersect the Sun...
but if the asteroid makes a close encounter with one of the inner planets
first, that can kick it out of the resonance, leaving a reasonably stable
orbit which is wholly or partly in the inner solar system. And that in
turn gives it time to have some chance of actually hitting one of the
inner planets.


--
Hop David
http://clowder.net/hop/index.html

In article ,
Hop David wrote:
Unfortunately, that *is* the group in question. There are zones within
the asteroid belt where resonances with Jupiter make orbits evolve very
rapidly and chaotically. When an asteroid's orbit, evolving very slowly
by more subtle processes, enters one of those zones...

The zones you speak of are the Kirkwood gaps?

Some of the resonances show as the Kirkwood gaps. Some are less obvious;
there is more than one kind of resonance.
--
MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer
pointing, 10 Sept; first science, early Oct; all well. |