* Astronomy

Transit of Venus Time Lapse

Third Contact: 04:31:39 UT

Venus' Transit and the Search for Other Worlds

Today, transit events are used to detect planets beyond the solar system. NASA's Kepler space telescope continuously measures changes in brightness of more than 150,000 stars to detect when a planet passes or transits in front of a star. Kepler does not directly image distant planets, as they are too far away.
Different-size planets block different amounts of starlight. Kepler's exquisitely precise photometer, or light sensor, is designed to detect fractional changes in brightness. For an Earth-size planet transiting a sun-like star, the change in brightness is only 84 parts per million. That is less than 1/100th of one percent, or the equivalent of the amount of light blocked if a gnat crawled across a car's headlight viewed from several miles away.
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Transit of Venus wows astronomers worldwide

Astronomers around the world looked to the sky last night and this morning to observe Venus as it passed across the face of the Sun for the last time this century. ESA's Sun-watching space missions also tuned in for the solar spectacular.
ESA's microsatellite Proba-2, situated in low-Earth orbit, tracked Venus as it moved across the solar disc over a period of nearly seven hours. Venus appears to wobble thanks to the slight up-down motion of Proba-2 and the large distance between the satellite and the Sun.
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Venus solar transit 2012 - Proba-2's journey across the Sun