Venus 2012
On Tuesday 5 June 2012, a rare astronomical event will take place when the planet Venus will move across the face of the Sun, visible on Earth as a small black disk as it passes directly between the Sun and Earth on its orbit.
In the early morning of 6 June 2012, the final stages of the transit of Venus will be visible from the UK on the eastern horizon as the sun rises.
After 2012, this planetary phenomenon will next take place in December 2117 and December 2125 – which means that the 2012 transit is a ‘once in a lifetime’ opportunity to witness this spectacle.
Green Templeton College, in collaboration with Oxford Astrophysics, is marking the transit with a series of special events centred around the historic 18th century Grade 1 listed Radcliffe Observatory, in its time one of Europe's finest astronomical observatories and now at the heart of Green Templeton College.
Whilst the Observatory was completed too late to see the 1769 transit of Venus, 2012 will be an opportunity to underline its contribution to our understanding of the science of astronomy.
Events planned include public lectures, family workshops, and a competition for young people.
See the full programme of events.
Find out more about the history of the Radcliffe Observatory.
What is a transit?
The transit or passage of a planet across the face of the Sun is a relatively rare occurrence. Transits are important because they offer astronomers a unique and rare opportunity to develop and test new techniques which can be applied to the detection of planets outside our own solar system.
From Earth, only transits of Mercury and Venus can be observed. But while there are on average 13 transits of Mercury each century, in contrast, transits of Venus occur in pairs with more than a century separating each pair. Transits of Venus occur only every 243 years, with pairs of transits eight years apart separated by gaps of 121.5 years and 105.5 years.
A transit of Venus is so rare that before 8 June 2004, when the last transit took place, no-one then alive had witnessed this planetary event which last happened in 1761 and 1769 and then 1874 and 1882. In fact only six such events have occurred since the invention of the telescope.
The 2012 transit begins at 23:03 on 5 June and ends at 05:54 on the morning of 6 June, making the final stages of the transit visible from the UK on the eastern horizon as the sun rises.
The entire transit will be widely visible from the western Pacific, eastern Asia and eastern Australia. Most of North and Central America, and northern South America will witness the beginning of the transit (on June 5) but the Sun will set before the event ends. Observers in Europe, western and central Asia, eastern Africa and western Australia will see the end of the event since the transit will already be in progress at sunrise from those locations.