Last Chance for a Century to Witness the Transit of Venus
01 Jun 2012



For the last time until the year 2117, people around the world will have a chance to witness the transit of Venus as the planet passes directly between Earth and the Sun on Tuesday 5th June.

Image of Venus pasing between the Earth and the Sun taken by Melbourne's photoheliograph.

​​​One of the surviving images taken by Melbourne's photoheliograph during the 1874 transit


For the last time until the year 2117, people around the world will have a chance to witness the transit of Venus as the planet passes directly between Earth and the Sun on Tuesday 5th June and Wednesday 6th June. The event will appear as a tiny black disk creeping across the Sun’s face.  Events are taking place for people to safely view this event and telescopes and space satellites will have the best seats to get close up details.

NOTE: Never view the Sun directly without a safe solar filter.

NASA’s Solar Dynamics Observatory, in orbit around the Earth, is scheduled to provide the best possible views of the event, producing the highest resolution, most detailed images ever taken of the Sun during a transit. RAL Space (based at STFC’s Rutherford Appleton Laboratory) not only provided electronics systems for the satellite’s cutting-edge cameras but is also a co-investigator on the mission.

Professor Richard Harrison, Principal Investigator for the UK instruments on STEREO and SDO Co-Investigator said “A transit is a wonderful and rare sight; when you consider the vastness of the sky, for a planet to pass the disc of the Sun is pretty unusual – and you do have to wait until 2117 for the next one. Although the view from the UK is rather limited this time, UK scientists will be using instruments aboard the NASA Solar Dynamics Observatory and the UK-led CDS instrument aboard ESA’s Solar and Heliospheric Observatory to witness this event from space. The sight will be spectacular from space but having a planet scanning across the Sun is valuable for a number of high-resolution scientific investigations of the solar atmosphere and for checking the optical performance of our instruments in space.”

In the UK, this very rare cosmic event will be visible low on the eastern horizon between around 4.45am and 5.55am on 6th June. A whole host of events will enable the public to make the most of the opportunity to observe and celebrate the transit of our ‘sister planet’.

Number of​ events (link opens in a new window) across the UK where people can get involved are available. In addition, Dark Sky West Midlands, a partner in STFC’s groundbreaking Dark Sky Discovery initiative, is inviting local enthusiasts plus amateur astronomers across the globe to take part in a Big Skype event at Birmingham’s Cannon Hill Park. Glasgow Science Festival is also running a special event where the public will be able to experience and enjoy the transit with expert help [1].

A key aim of scientists’ observations will be to help develop and refine techniques for discovering and characterising planets beyond our solar system by observing them as they pass across the faces of their parent stars. 

As well as SDO, the 15m-diameter James Clerk Maxwell Telescope, located in Hawaii and part-funded by STFC, will be observing the transit of Venus directly. A special fabric screen will protect its delicate instrumentation from damaging solar radiation but will allow through the submillimetre wavelength light that the telescope is designed to observe. 

This will also be the first transit of Venus to take place with a spacecraft in orbit around that planet. The European Space Agency’s Venus Express probe was launched in 2005 with UK involvement, including RAL Space closely involved in providing its ASPERA-4 instrument, which is helping to study the Venusian atmosphere. Venus Express will make observations of the planet during the transit for detailed comparison with those made back on Earth.

Overall, the transit of Venus will last just seven hours and will not be visible in every part of the world. For anyone observing the transit, it is essential not to look at the Sun (even wearing sunglasses) without using an approved solar filter, and not to try to observe the transit directly through binoculars or a telescope.

Transits of Venus occur in pairs, but with over a century between each pair due to the fact that the orbital planes of Venus and the Earth are not exactly aligned. The last transit occurred in 2004 and the next pair will not take place until 2117 and 2125. In previous centuries, observing these events enabled astronomers to calculate the size of our solar system.

Although very similar to the Earth in size, mass and age, Venus is a ferocious world with a brutal environment where the sky rains sulphuric acid and the atmospheric pressure is nearly 100 times greater than on our own planet.

Notes for editors

[1] University of Glasgow (link opens in a new window) website

An image of the transit of Venus from SDO (link opens in a new window) will be available after the event.


Lucy Stone
Press Officer
STFC Rutherford Appleton Laboratory
Tel: (0)1235 445627

Further information

View more information on Dark Sky Discovery (link opens in a new window).

For more information please contact: RAL Space Enquiries