Venus at Sunrise
Transit of Venus
This Tuesday or Wednesday, depending on where you live, sky-watchers around the world will be able to see a cosmic spectacle known as a transit of Venus. The events are so rare that only six Venus transits have been observed since the invention of the telescope more than 400 years ago.
A transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and Earth, becoming visible against (and hence obscuring a small portion of) the solar disk. During a transit, Venus can be seen from Earth as a small black disk moving across the face of the Sun. The duration of such transits is usually measured in hours (the transit of 2012 lasted 6 hours and 40 minutes).
The last transit of Venus was on 5 and 6 June 2012, and was the last Venus transit this century; the prior transit took place on 8 June 2004. The previous pair of transits were in December 1874 and December 1882. After 2012, the next transits of Venus will be in December 2117 and December 2125
