By Rod Hill on 2012-05-14
The Moon passes in front of the Sun on Sunday, May 20, bringing an annular eclipse to the border between Oregon and California and a partial eclipse to the rest of the Pacific Northwest. OMSI and Rose City Astronomers Club will host an eclipse viewing party at the east parking lot of OMSI. The free event will begin at 4:30 p.m., feature live, dramatic interludes by Portland Taiko, a premiere local Japanese drumming ensemble, and end at 7:00 p.m. Filtered solar telescopes and special viewing glasses will be available for safely viewing the Sun.
This unique phenomenon occurs when the Moon is directly between the Earth and the Sun, but at a farther distance from the Earth than with a total solar eclipse. As a result, the Moon appears too small to completely cover the Sun, and we observe the Sun as a ring (or “annulus”) surrounding the Moon. At 6:24 p.m. PDT, viewers along the center line in southwestern Oregon will see the Moon block 87% of the Sun's diameter; this will last 4 minutes and 47 seconds. A much broader region – from as far north as the Arctic Circle to the southern Pacific Ocean - will experience a partial solar eclipse. The path of annularity will be visible from China to the southwestern United States.
For Portland, the eclipse gets underway at 5:04 p.m. when the Moon makes first contact with the Sun. The maximum eclipse accords at 6:21 p.m. when the Moon covers 81 percent of the Sun's diameter at 25 degrees above the western horizon. The partial eclipse will end at 7:29 p.m. as the Moon exits.
Most important, do not view any of this eclipse without eye protection. Even during the annular phase, the Sun shines brightly enough to damage your eyes if the eclipse is observed without a protective filter. Use only an approved solar filter which blocks dangerous ultraviolet and infrared radiation as well as visible light. The special solar viewing glasses are available at the OMSI Science Store for $1.99.
This will be the first annular eclipse visible in the United States since May 10, 1994. The last partial solar eclipse for Oregon was on June 10, 2002. After the May 20 eclipse, the next partial eclipse will be on October 23, 2014. The next annular eclipse for the U.S. won't come until October 14, 2023. Before then, observers will have the good fortune to enjoy an even more spectacular eclipse: a total eclipse visible from most of Oregon, on August 21, 2017.
Learn how to view the eclipse with the experts and be a part of the event at OMSI! For more information or to check for possible weather-related cancellations, call the OMSI Star Parties Hotline, 503.797.4610 #3 then #5, or check the OMSI Star Parties web site: http://www.omsi.edu/starparties
Google Map: http://xjubier.free.fr/en/site_pages/solar_eclipses/ASE_2012_GoogleMapFull.html
WARNING: ANY TYPE OF SOLAR ECLIPSE IS NOT SAFE TO VIEW WITHOUT ADEQUATE EYE PROTECTION
Sunglasses DO NOT provide adequate eye protection: http://eclipse.gsfc.nasa.gov/SEhelp/safety.html
Jim Todd
OMSI Planetarium Manager
(Courtesy Mr. Jim Todd)
Closest Full Moon Of The Year