Re: historical astronomy question

[Rondo JEFFERY <RJEFFERY@WEBER.EDU>]

Larry asked:

> > > Larry.Smith@SNOW.EDU 10/17/00 02:42PM >>>
> Did Galileo ever see a transit of Venus?


  Transits of Venus are relatively rare, occuring only about every 120 years or so.  They occur in pairs, eight years apart, at that interval.  According to the Cambridge Encyclopedia of Astronomy I have, there was a transit of Venus on Dec. 4, 1639.  That was about three years before Galileo died, so there is the possibility for him to have seen it.  However, I have never read anything to say that he was still making astronomical observations at that late stage of his life.  Of course, it would have been made more difficult by his blindness (or near blindness).
  My copy of the Cambridge Encyclopedia does not list a second transit 8 years before or after the one in 1639, but does list other pairs in 1761/1769 and 1874/1882.  Does any one have better information, or know for sure if Galileo saw a transit?
  By the way, the next transits of Venus are listed in the Cambridge Encyclopedia as being on June 7, 2004, and June 5, 2012.  On the other hand, my old copy of Baker's Astronomy (1959, 7th ed.) lists them as coming on June 8, 2004 and June 6, 2012.  Any one know which is correct?

Rondo Jeffery
Physics Dept.
Weber State University
Ogden, UT 84408-2508
801-626-6202
rjeffery@weber.edu