Transit of Venus, 2012
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The next transit of Venus will occur on June 5–June 6 in 2012.
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Where visible
The transit will be best viewed from the Pacific Ocean. North America will be able to see the start of the transit, while South Asia, the Middle East, and most of Europe will catch the end of it. The transit will not be visible in most of South America or western Africa. The regions from which the transit is visible are shown in the map to the right.
When visible
Transit start and end times (in UTC) are given for various international cities (http://sunearth.gsfc.nasa.gov/eclipse/transit/venus/city12-1.html) and for various US cities (http://sunearth.gsfc.nasa.gov/eclipse/transit/venus/city12-2.html).
Recall that these times are in UTC. Add or subtract the appropriate amount for your time zone.
How to observe
DO NOT LOOK DIRECTLY AT THE SUN.
Besides possibly damaging your eyes, you won't be able to observe Venus this way anyway. The safest method for observing the Sun is projecting an image onto a screen, such as a piece of paper or card. This can be done by using either a piece of paper or card (such as a paper plate) with a pinhole in it, or a lens such as a telescope or binoculars (with one lens covered). The image to the right demonstrates how this can be done with two paper plates, the front one containing a pinhole.
Note that for a pinhole camera to show a Venus transit, the pinhole shold be about one millimeter wide, the distance between the plates about two meters, and the second plate must be in shadow, preferably inside a room. If the whole apparatus has open sides and is surrounded by sunlight, the projected image will be too weak to be seen. Practical experience shows that the pinhole method rarely produces an image large enough or sharp enough to view the transit. It certainly is not possible to get accurate contact times using a pin hole camera.
Alternatively, a welding mask can be used to filter out the intense light (these are often used to view solar eclipses). To test whether the viewing plate is effective enough to block harmful solar glare, look at a 100 Watt filament bulb through the mask. You should see nothing more than the filament; be sure to check for imperfections where light leaks through small holes in the material.
See also
External links
- HM Nautical Almanac Office: 2012 Transit of Venus (http://www.nao.rl.ac.uk/nao/transit/V_2012/)