On Mon, 26 Sep 2005 00:10:22 GMT, "SimBrain" etched in
cyberspace:

Hello. Does anyone know if comets travel from stars to other stars? Or are
they limited to just 1 solar system?


Yes

comets in parabolic or hyperbolic orbits will have come from out side
the solar system and will escape again unless disturbed by a planet.
Most hyerbolic comet had a e=-0.0007.

Have a look at http://www.apl.ucl.ac.uk/lectures/3c37/3c37-12.html to
see how big the Oort cloud of comets is. This article states that the
edges of the cloud would be trimmed off by passing stars, but equally
the Sun would trim off the comets from that other star,
so there could be a deal of comet swapping taking place.

During the early solar system Jupiter likely accelerated many comets
out of the solar system, similarly there should be comets travelling
out of control from other forming solar systems.

How thickly is space filled with comets? If there were too many they
would blank out the star light, and crash into each other making
flashes of light appear in the sky. Since this is not observed they
can't be too thick.

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