Solar eclipse of May 20, 2012

An annular solar eclipse occurred at the Moon’s descending node of orbit between Sunday, May 20 and Monday, May 21, 2012, with a magnitude of 0.9439. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. An annular solar eclipse occurs when the Moon's apparent diameter is smaller than the Sun's, blocking most of the Sun's light and causing the Sun to look like an annulus (ring). An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres or miles wide.

The eclipse was visible in a band spanning through Eastern Asia, the Pacific Ocean, and North America. As a partial solar eclipse, it was visible from northern Greenland to Hawaii, and from eastern Indonesia at sunrise to northwestern Mexico at sunset. The moon's apparent diameter was smaller because the eclipse was occurring only 32 1/2 hours after apogee.

The annular eclipse was the first visible from the contiguous United States since the solar eclipse of May 10, 1994 (Saros 128), and the first in Asia since the solar eclipse of January 15, 2010 (Saros 141). The path of the eclipse's antumbra included heavily populated regions of China and Japan, and an estimated 100 million people in those areas were capable of viewing annularity. In the western United States, its path included 8 states, and an estimated 6 million people were capable of viewing annularity. It was the 58th eclipse of the 128th Saros cycle, which began with a partial eclipse on August 29, 984 AD and will conclude with a partial eclipse on November 1, 2282.

Visibility and viewing
The antumbra had a magnitude of .94, stretched 236 km wide, and traveled eastbound at an average rate of 0.62 mile per second, remaining north of the equator throughout the event. The longest duration of annularity was 5 minutes and 46 seconds, occurring just south of the Aleutian Islands. The eclipse began on a Monday and ended on the previous Sunday, as it crossed the International Date Line.

Asia
The annular eclipse commenced over the Chinese province of Guangxi at sunrise, at 6:06 a.m. China Standard Time. Travelling northeast, the antumbra of the eclipse approached and passed over the cities of Macau, Hong Kong, Guangzhou, and Xiamen, reaching Taipei by 6:10 a.m NST. After crossing the East China Sea, it passed over much of eastern Japan, including Osaka and Tokyo at 7:28 a.m and 7:32 a.m JST respectively, before entering the Pacific Ocean. The penumbra of the eclipse was visible throughout Eastern Asia and various islands in the Pacific Ocean until noon.

The path of the antumbra over highly populated areas allowed at least an estimated 100 million people to view annularity. Because the eclipse took place during the summer monsoon season in Southeast Asia, viewing conditions were not ideal in some areas, including Hong Kong.

North America
After traveling approximately 4,000 miles (6,500 kilometers) across the Pacific Ocean, the antumbra entered North America between the coastlines of Oregon and California, reaching the coastal city of Eureka, California at 6:25 p.m PDT. After passing over Medford, Oregon and Redding, California, it had reached Reno, Nevada by 6:28 p.m PDT. The eclipse continued to travel southeast, passing 30 miles (48 km) north of Las Vegas, Nevada, over St. George, Utah, and reaching the Grand Canyon by approximately 6:33 p.m MST. After passing over Albuquerque, New Mexico and Lubbock, Texas, the eclipse terminated above central Texas at sunset, 8:38 p.m. CST. An estimated 6.6 million people lived under the path of the antumbra. The penumbra was visible throughout most of North America, including the islands of Hawaii.

Eclipses of 2012

 * An annular solar eclipse on May 20.
 * A partial lunar eclipse on June 4.
 * A total solar eclipse on November 13.
 * A penumbral lunar eclipse on November 28.

Metonic

 * Preceded by: Solar eclipse of August 1, 2008
 * Followed by: Solar eclipse of March 9, 2016

Tzolkinex

 * Preceded by: Solar eclipse of April 8, 2005
 * Followed by: Solar eclipse of July 2, 2019

Half-Saros

 * Preceded by: Lunar eclipse of May 16, 2003
 * Followed by: Lunar eclipse of May 26, 2021

Tritos

 * Preceded by: Solar eclipse of June 21, 2001
 * Followed by: Solar eclipse of April 20, 2023

Solar Saros 128

 * Preceded by: Solar eclipse of May 10, 1994
 * Followed by: Solar eclipse of June 1, 2030

Inex

 * Preceded by: Solar eclipse of June 11, 1983
 * Followed by: Solar eclipse of April 30, 2041

Triad

 * Preceded by: Solar eclipse of July 20, 1925
 * Followed by: Solar eclipse of March 21, 2099