Transit of Venus across the Disk of the Sun
No person alive today has seen the Transit of Venus across the disk of
sun that last occurred on 6th of December 1882. There
have been only 5 previous transit observed by humans the first in
1639, 1761, 1769, 1874, and 1882.
If it is clear we will observe it from sunrise around 5:43AM until it
around 7:26AM in the morning from the roof of the Parking Garage
Fenton and King Street on Tuesday, June 8, 2004. If it is
cloudy and predicted to continue that way well past the event then we
have a show in the planetarium watching web cams of this
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 6 opportunity to use this method with
the transit of Venus across the disk of the Sun. Come join us for
this scientifically historical event. The next transit of Venus
occurs in 8 years in 2012, but then it will be visible from here near
sun set, and you can not afford to wait until 2117.
Snoozers on this earlier morning event will be losers.
Sun Earth Day Transit of Venus pages.
Espenak's Transit of Venus pages.
Transit of Venus & the Quest for the Solar Parallax by David
lots of stuff.
1882 Transits of Venus: Observed from Wellington, South Africa.
Project, European Southern Observatory.
it looked like photographically in 1882.
made by Lou Mayo for this event in Power Point.
- Free Parking in the Parking Garage on floors one through
four. Fifth floor roof reserved for telescopes and people.
- Internet Cafe on the first floor of the Parking Garage, where we are guaranteed views of the Sun.
- Transit with TRACE
from orbit, no clouds for sure. Near the earth so it does not
miss the alignment.
- Transit with SOHO
from orbit, no clouds but it misses from it position, but will be
visible across the corona.
- Transit from Greece via
the San Francisco Exploritorium, direct public
web broadcast link.
- Transit from Norway.
- Transit from Portugal.
- Transit from Switzerland.
- Transit from the Saros
group, physically Islas Canaria.
- Real viewing of the Sun and the transit of Venus on the roof
(fifth floor) through many telescopes, all with safe filters, some with
H-alpha filters. Several projectors of the disk of the Sun
viewable by all, but with less resolution than the telescope
views. All roof top views
depend upon clouds not being in front of the Sun when you view. You
too can duplicate Jerimiah Horock's calculation of the distance of the
Earth to the Sun, 1 AU, by assuming that Venus and Earth are the same
size while you are on the roof. Calculators provided for those
who do not want to do the multiplication and long division by hand,
like Horock's did. It is a surprisingly simple
calculation. Come and measure, rulers provided, and learn with
us. Montgomery College is the community's college.
- As an extra treat you may listen to the cicadas, which may make
you wonder when last did Brood X Cicadas and the Transit of Venus
across the disk of the Sun last occur. The answer seems to
be May 22, 797AD and May 23, 921 BC before that, see http://www.transitofvenus.org/cicadas.htm
for more details. See how
special this day is, please join us for this special event.
- Reflection on the transit:
- Crowd was good, around 500 people enjoyed at least part of the
one hour 26 minutes transit visible to us at Takoma Park, Maryland,
- Dr. Tom Van Flandern who helped me view the 3 and 4 contact
with the college's new 10 inch Meade LX200 GPS SMT, under fairly high
magnification for a solar image, has the best explanation of the black
drop effect that I have seen and how what was perceived as a
disadvantage can be turned into an advantage. After looking at
TRACE images where there is no Earth's atmosphere, I am convinced that
Tom is right. His physics also makes sense, too. Tom is
good at many things; he is also responsible for explaining how Solar
Eclipse views are best on the edge instead of the centerline. In
1991, I went to an Eclipse Edge expedition in Sayulitia, Mexico on July
11 with a group lead by Tom.
- I want to especially thank Dr. Nancy Grace Roman, John Abbott,
Lou Mayo, Jay Miller, and all of the other people who brought
telescopes and made this public scientific event such a
delight. It is great to have good friends. It is also
great to have students like Jon Hellerman, Matthew Bowman, Leigh Gold,
Nahanda Tankasala, LaMarkus Williams, and Julie Jaques and her son
Francis. Montgomery College really is the communities
college. I also want to thank all of the
people who helped me with publicity within
the college like Steve Simon, Elizabeth Holman,
- Image above taken by John Abbotts, a composit of images
taken form the Roof of the Parking Garage at Montgomery College.
If this is not cool, I don't know what is.
- Image taken by Tomas Maruska
Rubinar 5.6/500 with Baader AstroSolar filter
WebCam Philips ToUCam Pro 740
1/10 000 sec at frame rate 30 im/sec
[Composite of 12 frames]
June 8, 2004, 10:09:18 UT
Stupava, Slovakia, which is not at the Parking Garage of Montgomery
College at Takoma Park, Maryland, USA, but this, too is way cool.
College's Planetarium home page
Last updated 9:20PM 6/21/2004 by Dr. Harold Williams