Transit of Venus
Dr Carolin Crawford and Dr Helen Mason , University of Cambridge
The Transit of Venus: 8 June 2004
Additional pictures of the Transit and the second videoconference
Talk given at the first videoconference
Participating schools' experiences on 8 June
Links to other Transit of Venus sites
Competition based on the Transit of Venus
On 8 June 2004, Venus crossed the sun, as seen from the Earth. The process started at about 6.23am (see left-hand photo, taken at Neatherd High School), and finished at about 12.23pm (UK time) (see right-hand photo). This has not happened for over a century since, unlike solar and lunar eclipses, which occur frequently, Venus only passes between us and the sun very occasionally. This is an amazing opportunity to observe the solar system in action, to watch the movement of a planet and make calculations on those observations.
The image on the left shows a photo of Venus taken on the evening of 13th March 2004. The planet-wide highly reflective clouds of Venus make for a featureless view for Earth-based telescopes. However the phases of the planet, first seen by Galileo in 1610, are easily viewed. In the coming months our view of the illuminated face of Venus will decrease
as the planet's orbit takes it between the Earth and the Sun. Venus will wane
until it has completely turned its night-time side to us when it transits the sun on the 8th of June.
The second image on the left shows what Venus looked like on 11 April. You can see that our view of it is decreasing.
The third image on the left shows what Venus looked like on 22 April. The sequence of photos shows it gradually waning.
This image shows the Moon, with a crescent illuminated by sunlight and the rest of the Moon illuminated
by earthshine (light reflected from the earth onto the disc of the Moon). Venus would be the same shape
if we could see it at this magnification. However, you can see how bright it is.
Observations were made in Britain and in S Africa in 1882, which was the first use of moving image photography. We are hoping to be able to repeat this, with schools from two areas in the UK (Norfolk and London), and from two parts of South African (Cape Town and Johannesburg).
Unlike other eclipses, Venus will not appear large, relative to the sun. It will be just about big enough to see with the unaided eye - BUT: no one should try to watch it directly, as this could result in serious eye damage, or even blindness. If you have links with a local astronomical society, who could help with expert advice on making the observations, and equipment, so much the better.
Motivate held a conference about this event. The materials below are those used by the participating students. They are now available for schools and individual students to use.
http://www.vt-2004.org/central/ contains resources made available by the European Southern Observatory.
http://www.transit-of-venus.org.uk/otday.htm has an interactive page, so that students anywhere can input their own measurements and obtain a value for the distance of the Sun from the Earth (but see our own spreadsheet for this as well)
Try this website for a competition based on the Transit of Venus: http://www.ras.org.uk/html/education/venus04.html
You might also like to look at the website Neatherd School, Dereham have created for their Astronomy Club. You can see here one of their pictures of the Transit of Mercury which occurred in 2003. Mercury is many orders of magnitude smaller than the sun, and is the black dot you can see towards the top right of the sun (the bigger dot near the centre is a sun spot). Venus is bigger than Mercury, although it is still very small relative to the sun, and will appear something like this on June 8.
Go to http://www.neatherd.org/astronomy/Our%20Star%20h.htm and follow links to Our Star* to find out what they are doing, and see their photos.