The 2004 Venus transit, seen near West Orange, N.J. (Copyright John Cudworth. All rights reserved.)
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› Overview: 2012 Venus Transit
› FAQ: About the Venus Transit
› Mission: Kepler Searches for Planets
› Video: 2004 Venus Transit in Ultraviolet One of the rarest astronomical phenomena, a transit of Venus, will occur on the evening of Tuesday, June 5. Similar to a solar eclipse, Venus will move across the face of the sun and block light from the sun to Earth. The planet's transit - the last Venus transit until 2117 - will take about six and a half hours to travel across the face of the sun. It will be viewable from many places around the world, and this map shows global viewing locations.
The transit of Venus also demonstrates how scientists on NASA's Kepler mission are detecting planets beyond our solar system. NASA's Kepler space telescope measures the change in brightness from distant stars when a planet passes or transits in front of the star. From the transit data, scientists can determine the size of the planet, the length of its year and calculate the distance the planet is from its star. Kepler has confirmed 61 planets and more than 2,300 planet candidates using the transit method.
About the Web Chat
On June 5, 2012, NASA experts answered your questions about the Venus transit.
› Chat Transcript (PDF, 545 Kb)