Transit of Venus, 2012

Posted June 05, 2012 by User 1

In under 24 hours, Venus will begin its journey across the face of the Sun as seen from the Earth. Such transits last about 6.5 hours and generally occur in pairs separated by 8 years which are in turn, separated by gaps of 105.5 and 122.5 years. The upcoming transit is the second of an 8 year pair with the first having occurred on June 08, 2004. The following transit after this one will occur on December 10, 2117.

Due to the parallax effect, contact times may be off by up to 7 minutes. First contact, when Venus' limb touches that of the sun, will occur at approximately 22:10 UT on June 5, 2012. Second contact, when the disk of Venus is first internally tangent to the disk of the Sun, occurs less than 20 minutes later at approximately 22:28 UT. Venus is closest to the Sun at about 01:30 UT on June 6, 2012 several hours later. After another several hours, Venus reaches third contact, being internally tangent to the Sun again, at 04:32 UT before exiting the Sun's disk completely at about 04:50 UT.

The transit favors the Pacific rim with best visibility being in the north-central Pacific just southeast of Japan. The entire world, except parts of Africa, Antarctica, South America and the Iberian Peninsula will be able to view at least some part of the transit provided that weather cooperates. A map of global visibility is provided here:

The key phrase above is "provided that weather cooperates." Over the United States, that will not be the case for about a quarter of the country. The Weather Channel has created a graphic which forecasts the predicted cloud cover for the event: The Southwest and Midwest will have near-perfect conditions with clouds and possibly rain for the other areas.

Good luck to everyone tomorrow and remember view the transit safely! (NASA provides a page on safe solar viewing practices:


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