you can have a look at the Neodys pages, where occasionally some
close encounter with planets and/or Ceres and Vesta are reported.
Very likely it is a side-effect of search for close encounters with
Earth, because for such a search they have funds. No funds to protect
Mars (the only place where you have a chance to witness an impact and
this is a clear sample:
As far as I know, Neodys does a systematic search only for Earth,
then track the other planets for the examined asteroids for the sake
of compute perturbation on their orbits.
If somebody has better hints, I am interested too to this topic. I
tried to get info e-mailing neodys' people, but even as an Italian I
didn't get any answer till now.
My purpose is to investigate on mutual asteroid collisions, an
intriguing problem... very few possibility, but a large amount of
possible pairing (considering about 300'000 in main belt, 9.0E+10
pairing) a big problem of number crunching and sorting out data...
It's very common an asteroid turns into comet, but some years ago
(shoemaker-levy already hit jupiter) a comet turned to asteroid,
since the coma and queue were peculiar and probably due to a
collision occurred... Unfortunatly I can't remember the exact
Comments appreciated too.
Pier Luigi Turrini