Transit of Venus across the Disk of the Sun
If it is clear we will observe it from around 5PM until sunset from the
roof of the Parking Garage
at
Fenton and King Street on Wednesday,
6 June 2012. If it is
hopelessly
cloudy and predicted to continue that way well past the event then we
will
have a show in the planetarium watching web cams of this
event.
The real thing is better!
The reason why transits of Venus across the disk of the sun are
important, aside from the spectacle and their rarity, is that is how we
know that we are 8.3 light minutes (149 million kilometers, 93 million
miles) away from the sun. By measuring the distance on the earth
between two observers and the small angular difference between the two
observers transit of Venus; we can scale up the earth distance to
give us the earth to Venus distance and from that the earth to the sun
distance of 1 AU (Astronomical Unit). All
other distances to planets, stars, and galaxies are based upon this
first close distance in our Solar System the AU. Before the AU
was determined in terms of some known value on the earth we could not
say how far the planets or stars or galaxies were away. All
distances off of the earth are based upon our determination of the
AU, and this is only our 7 opportunity to use this method with
the transit of Venus across the disk of the Sun. Come join us for
this scientifically historical event. You can not afford to
wait until 2117.
We had good luck on June
8, 2004 in the morning when we saw this event with around 500
people on the roof of the parking garage.
For transit visibity world wide go to this image.
Montgomery
College's Planetarium home page
Last updated 4:46PM 11/16/2006 by Dr. Harold Williams