What time is the 2012 transit of Venus and how can I see it?

Transit of Venus 2004

This is your last chance to see a transit of Venus for 100 years. Here’s how…

LAST UPDATED AT 12:12 ON Tue 5 Jun 2012

BARRING a huge leap in human life expectancy over the next century, tomorrow morning will be the last chance to see the transit of Venus for most people alive today. So what is this spectacular astronomical phenomenon, and how can one see it?

WHAT IS THE TRANSIT OF VENUS?
An astronomical phenomenon in which the planet Venus, when viewed from Earth, appears to move across the face of the Sun. Transits happen in eight-year pairs every century or so. This year’s transit is the second of the current pair, the first of which was observed in 2004 and is photographed above. The next transit of Venus isn’t due until December 2117.

WHO CAN SEE THE TRANSIT OF VENUS?
Almost all the Earth’s population has a chance of seeing the transit of Venus, weather permitting. However, you’re out of luck if you live in west and southern Africa and most of South America.

WHAT TIME IS THE TRANSIT OF VENUS?
In the UK, the transit will begin at 11.09pm British Summer Time tonight (5 June) and end at 5.49am tomorrow morning. As sunrise is at 4.45am, and the weather forecast is cloudy for virtually all the UK, the chances of a clear view of the transit are small. A full map of transit viewing times is available here.

WHO WILL GET THE BEST VIEW OF THE TRANSIT?
Most of Australia, Japan, the Philippines, most of China and much of Russia are among the regions which will see the transit in its entirety. Photographers in the United States will perhaps have the most romantic view, as the phenomenon coincides with their sunset.

HOW CAN I VIEW THE TRANSIT OF VENUS?
Do not look directly at the Sun – particularly not through binoculars or a telescope. Nasa suggests a #14 welder's glass – or projecting the view through a telescope onto a screen. Another option is to watch the whole transit on the internet. Nasa is hosting a live Venus transit webcast from Mauna Kea in Hawaii.

IS THERE ANY SCIENTIFIC SIGNIFICANCE TO THE TRANSIT?
In the past, transits of Venus have been used to determine the distance between the Sun and the Earth, by observing the event simultaneously at different locations on our planet’s surface.

One such attempt was made in the 1760s, when Captain James Cook was sent to Tahiti to view a transit of Venus. Unfortunately, primitive equipment prevented precise measurements from being taken and we would have to wait until a transit in the late 1800s to gather precise enough data to work out the size of the solar system.

Tonight’s transit will be of interest to scientists involved in studying planets around distant stars – exoplanets. The Kepler telescope has discovered thousands of potential planets by studying how stars interact with the worlds that orbit them. By observing how a well-studied world such as Venus appears against its star, scientists will be able to make assumptions about the composition of faraway planets. · 

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