|Transit Of Venus 2012 Path (NASA)|
The rare spectacle will last for nearly 7 hours, from 22:09 UTC on June 5th until 04:49 UTC on June 6th.
Here's a sampling of local viewing times: 12:10 p.m. Honolulu; 3:06 p.m. Los Angeles; 5:06 p.m. Mexico City; 6:04 p.m. New York — all on Tuesday — and 5:37 a.m. London; 6:09 Manila; 6:10 a.m. Beijing; 6:12 a.m. Hong Kong; 6:38 a.m. Cairo; 7:10 a.m. Tokyo; 8:16 a.m. Sydney; 10:15 a.m. Auckland on Wednesday.
A Venus Transit takes place when Planet Venus passes directly between the Earth and the Sun. But considering the small size of the planet, the Transit is only seen as a small black disk moving across the face of the Sun.
The transits of Venus occur in pairs with more than a century separating each pair. Since the invention of the telescope, there have been only eight of such events that have occurred - 1631, 1639, 1761, 1769, 1874, 1882, 2004 and the upcoming one this June 2012. The 2004 and 2012 transits form a contemporary pair separated by 8 years. The next two transits of Venus will occur on 2117 and 2125.
One should take precautions in watching the Sun during these hours as staring at it without precaution can damage one's retina. The safest manner is to project the image of the Sun through pinholes, telescopes or binoculars onto a screen or by using a filter to shield the naked eye.