Black bear eating from my apple tree, August night, 2012

Sunday, June 3, 2012

Transit of Venus

On Tuesday, June 5, 2012, Americans will be treated to a rare astronomical event --the Transit of Venus. The planet Venus will be positioned between the sun and the earth, so Venus will appear as a dot against the sun. Check out the Transit of Venus web site for all you need to know about witnessing this spectacle. Why is the transit so rare? Here's the answer form the web site:

Transits of Venus have a strange pattern of frequency.  A transit will not have happened for about 121 ½  years (prior to 2004, the last one was 1882).  Then there will be one transit (such as the one in 2004) followed by another transit of Venus eight years later (in the year 2012).  Then there will be a span of about 105 ½ years before the next pair of transits occur, again separated by eight years.  Then the pattern repeats (121 ½ , 8, 105 ½ , 8).

Also from the site, a blurb chock-full of helpful links:


Whether and when you can see the 2012 transit of Venus depends on your location.  Key highlights include the four "contacts" near the beginning and end of the transit when Venus appears to touch the edge of the sun.  Most of North America sees the beginning of the transit in the afternoon and evening (find a clear western horizon!) on June 5, whereas much of Eurasia sees the end of the transit in the morning (find a clear eastern horizon!) on June 6.
Click to access and enlarge PDF version of map showing visibility of 2012 transit of Venus.  Courtesy of Fred Espenak (NASA GSFC), who provides additional transit of Venus data from NASA.

QUICK TIP:  For date and times of the transit of Venus itself at your location, see Local Transit Times.  For an interactive map showing events near you, see NASA Sun-Earth Day Event Locations.


Of course, you can't just stare up at the sun to view the transit, or you'll severely damage your eyes. Proper solar viewing devices must be used. Some people recently picked up solar glasses to view the recent solar eclipse, and those will work just fine. The Transit web site has resources for obtaining viewing devices that provide proper eye protection. Another option, especially if your location happens to be cloudy in late afternoon and early evening, is to view the transit safely in real-time via the web. Once again, go to the Transit web site for more information, and enjoy.






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