What is the Transit of Venus 2012?

Transit of Venus: vaguely Odyssian-sounding, involving the Roman goddess of love and beauty. But what is it?

The phenomenon takes place when Venus aligns directly between the Sun and Earth. During the 6-hour transit on June 5th-6th, the planet will appear as a small black disk moving across the face of the sun.

Transits of Venus are some of the rarest celestial phenomena that can be predicted. They occur in a pattern that repeats every 243 years, in which a pair of two transits is separated by eight years and each pair itself is separated from others by longer periods of 121.5 years and 105.5 years. Although we last saw one in 2004, this year’s transit will be the last transit of the century. The next one will be in 2117.

Scientists will be sitting front-row at the celestial performance. Venus transits historically helped astronomers gain the first realistic estimates of the size of the Solar System and distances between the Earth and the Sun. This year’s transit will provide scientists with many research opportunities, such as refinement of techniques to search for planets outside of the Solar System. 


To watch the planet crawl across the star, use a telescope, binoculars, pinhole, or reflected pinhole. These technologies project images of the Sun onto a screen so you won’t damage your eyes. 

People in the Western Pacific Ocean, northwest North America, northeastern Asia, Japan, the Philippines, eastern Australia, New Zealand, and high Arctic locations such as Scandinavia, Iceland, and Greenland will be able to see the entire transit this year. In the rest of North America, the Caribbean, and northwestern South America, observers will be able to see the beginning of the transit on June 5th until sunset. In South Asia, the Middle East, east Africa, and most of Europe, people will be able to observe the end of the transit from sunrise on June 6th. Most of South America and West Africa will not be able to view the transit.

It’s the last time we’ll be able to watch our sister planet dance across the largest stage in our Solar System. Let’s give her our time of night.