It may be interesting to note that during the years 2007-2049
there are 25 transits of asteroids with definitive numbers in
the range 1-145705 over the Sun. The list is given on page 323
of my 5th Mathematical Astronomy Morsels book. The next two
events are a transit of asteroid (141079) 2001 XS30 on 2012
May 31, and a transit of (85953) 1999 FK21 on 2012 Sep. 25.
It may come as a surprise that there are much more asteroidal
transits over the tiny disks of the planets Jupiter to Neptune.
During the year 2007 alone, for the asteroids with numbers 1 to
125000, there were 12 transits over Jupiter, 16 over Saturn,
6 over Uranus and 5 over Neptune. Of course, at such transits
the transiting asteroid is not dark as for transits over the Sun,
but it is almost fully illuminated.
On 2011 December 22 there will be a transit of (650) Amalasuntha
over Jupiter.
With the excellent software "Solex" of Dr. Aldo Vitagliano it is
rather easy to find such asteroidal transits.
Jean Meeus
[Non-text portions of this message have been removed]