Mark your calendar for Sunday, May 20, 2012. The Moon will pass in front of the Sun but not completely block it, creating what scientists call an annular solar eclipse.

This is the first solar eclipse of the year, and the first annular eclipse to be seen from the United States in 18 years. The event starts May 21 at dawn in eastern Asia – the city of Guangzhou in southern China sits within the eclipse path, as do Tokyo, Osaka, and Yokohama in Japan, along with Hong Kong and Taipei.

Annular Eclipse
On January 4, 2011, the Japanese satellite Hinode captured this breathtaking image of an annular solar eclipse. Hinode/XRT/NASA/NAOJ/STFC/ESA/NSC

As the eclipse path moves eastward across the Pacific, it will cross the International Dateline before entering the California / Oregon border, where it will still be May 20. The Moon’s shadow passes in the late afternoon over Nevada, Utah, Arizona, a corner of Colorado, New Mexico, and the annular eclipse ends at sunset in Texas.

The American cities that will see the annular eclipse are Grants Pass, Medford, Eureka, Redding, Chico, Reno, Carson City, St. George, Farmington, Albuquerque, Santa Fe, Clovis, Roswell and Lubbock. More than 30 U.S. national parks lie within or very near the path as well, and most of North America will witness at least a small bit taken out of the Sun.

An annular eclipse occurs when the Sun and Moon alignment is perfect but the Moon is near its greatest distance from Earth; its disk is not then large enough to cover the photosphere completely, and a ring of sunlight is left showing round the dark mass of the Moon (Latin annulus, a ring). On May 20, the Moon will cover only 88-percent of the Sun.

Important: Because the Sun’s disk will not be completely covered, you must use special “eclipse glasses” (not regular sunglasses) or some other safe solar viewing method during the eclipse.

To find out more about solar eclipses, please visit our page “All About Solar Eclipses”.

Path of the Annular Eclipse
Path of the annular (ring) solar eclipse of May 20, 2012 over the southwestern part of the United States.