Yahoo! News - Venus Begins Rare Transit of Sun
LONDON (Reuters) - Venus began a transit across the sun on Tuesday for the first time in more than a century.

Unlike a solar eclipse by the moon that is over in two or three minutes, Venus's transit -- which last occurred in 1882 -- will go on for six hours. The planet will appear as an intense black dot, looking tiny on the solar disc.

Venus was crossing from bottom left of the solar disc to the right and will be 26.7 million miles from earth.

"Venus will be about 1/30 the size of the diameter of the sun, but it will be much darker and more intense than sunspots," said Dr Robert Walsh, of the University of Central Lancashire's Center for Astrophysics in northern England.