Parking Orbits for Comets and Asteroids

Is it the Oort outer belt (outside of Pluto) or the Kuiper belt? What
gave comets their great elliptical orbits. I would think a round orbit
was closer to the reality of gravity.Seems to me comets should in time
line up with the surface of the sun and hit. We watch Jupiter being hit
by a comet.(famous pictures) I really don't see much difference than a
comet or an asteroid,but I'll bet on a comet that hit the Earth 130
million years ago as being the one that wiped out most of the cold
blooded animals,and made room for us mammals. Bert

Both are sources for comets. The Kuiper belt, outside the orbit of Neptune,
is reponsible for many of the shorter period comets, most of which orbit
near the ecliptic. The Oort cloud is further out, spherical in shape, and
is where most of the long period comets come from. Because of its shape,
comets can drop in from any direction. But remember that gravity permits
the trajectories of objects to follow any of the conic shapes---a line,
hyperbola, parabola, ellipse, or circle---depending on the circumstances.
None is favored.

Some comets come in along very thin ellipses (or parabolas) and do hit the
Sun. There are plenty of SOHO images showing this. Others have perihelions
many astronomical units out are in no danger at all (unless further
perturbed by a planet).



"G=EMC^2 Glazier" wrote in message
...
Is it the Oort outer belt (outside of Pluto) or the Kuiper belt? What
gave comets their great elliptical orbits. I would think a round orbit
was closer to the reality of gravity.Seems to me comets should in time
line up with the surface of the sun and hit. We watch Jupiter being hit
by a comet.(famous pictures) I really don't see much difference than a
comet or an asteroid,but I'll bet on a comet that hit the Earth 130
million years ago as being the one that wiped out most of the cold
blooded animals,and made room for us mammals. Bert

Hi Bill Thanks for that information. I wonder if we can tell which
belt(outer or inner) that was the home of the asteroid. Like maybe the
asteriods in the Oort belt have fewer crater marks? Those asteroids have
to be very old rocks to have been hit so many times. I wonder if there
were ever some asteroids that were solid cubes of ice? The close up
picture the Galilleo probe took of Gaspra is outstanding. These
asteoids all have round edges(look like potatoes) I find that
interesting. Did space dust smooth out any sharp edges over billions of
years? Bert

I think you've got it backwards. Objects in the Oort cloud and Kuiper belt
evidently formed closer to the Sun (greater density when the solar system
was forming) and got flung outward by gravitaional encounters with larger
bodies. The main asteroid belt between Mars and Jupiter consists of small
bodies that formed at that location but were never able to accrete into a
planet because of Jupiter's influence. It kept things too stirred up.

http://seds.lpl.arizona.edu/nineplan...nets/kboc.html




"G=EMC^2 Glazier" wrote in message
...
Hi Bill Thanks for that information. I wonder if we can tell which
belt(outer or inner) that was the home of the asteroid. Like maybe the
asteriods in the Oort belt have fewer crater marks? Those asteroids have
to be very old rocks to have been hit so many times. I wonder if there
were ever some asteroids that were solid cubes of ice? The close up
picture the Galilleo probe took of Gaspra is outstanding. These
asteoids all have round edges(look like potatoes) I find that
interesting. Did space dust smooth out any sharp edges over billions of
years? Bert