Hi Arild,

As you suspected, Guide doesn't understand the idea of multiple-object
conjunctions. I suppose it _could_, in theory... but at least right now,
it doesn't.

Best I can do to make that search a little less difficult is the following.
Under Tables... Miscellaneous Tables, you'll see "Transits of Venus, -2000
to +6000". If you download the following and put it in your Guide folder:

http://www.projectpluto.com/ven_tran.etb

and are running Guide in English, then the table will still be labelled
-2000 to +6000, but the actual list will cover the years -20000 to +34000.

The accuracy with which it does so is somewhat questionable. The transit
computations were done using the "short Meeus" version of the VSOP planetary
algorithm, with higher-precision terms omitted. Guide will show the actual
positions using full VSOP. Within the range of, say, -2000 to +6000 (the
intended range of VSOP), agreement is very close, as described at

http://www.projectpluto.com/accuracy.htm#distant

...but as you get outside the valid range of VSOP, planetary positions
start to become inaccurate. I can't really quantify that statement,
unfortunately, but at some point, I'd assume the transit results become
meaningless. (I think this could be fixed, were one to integrate the
planetary motions beyond the range covered by the JPL ephemerides and
by VSOP.)

The question of a simultaneous transit/solar eclipse may be of greater
interest, since there are plenty of opportunities for that to happen.
Transits of Mercury occur about once every seven years; solar eclipses
occur a bit over twice a year. A ballpark estimate: each event takes
about three hours or so, on average. A given transit would have about
one chance in 700 of having at least some overlap with a solar eclipse.
For Mercury, the co-incident transit/solar eclipse would occur about
once every 5000 years.

Transits of Venus occur about once every sixty years, so you'd get
one happening at the same time as a solar eclipse about once every 40000
years. Simultaneous transits would occur about once every half million
years or so. (Please note that the above figures are pretty rough. I
basically looked at a few eclipses and transits and their average lengths.
But they should be in the right area.)

-- Bill