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. An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres or miles wide. Occurring about 1.3 days after apogee, the Moon's apparent diameter was smaller.
The annular eclipse was the first visible from the contiguous United States since the solar eclipse of May 10, 1994, and the first in Asia since the solar eclipse of January 15, 2010. The path of the eclipse's penumbra and antumbra#Antumbra|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.
The eclipse was visible in a band spanning through East Asia, the Pacific Ocean, and North America. As a partial solar eclipse, it was visible from Greenland to Hawaii, and from eastern Indonesia at sunrise to western North America at sunset.

Visibility and viewing

The antumbra had a magnitude of.94, stretched wide, and traveled eastbound at an average rate of 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 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 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.

Eclipse details

Shown below are two tables displaying details about this particular solar eclipse. The first table outlines times at which the Moon's penumbra or umbra attains the specific parameter, and the second table describes various other parameters pertaining to this eclipse.
EventTime
First Penumbral External Contact2012 May 20 at 20:57:13.9 UTC
First Umbral External Contact2012 May 20 at 22:07:23.9 UTC
First Central Line2012 May 20 at 22:10:08.2 UTC
First Umbral Internal Contact2012 May 20 at 22:12:53.7 UTC
Ecliptic Conjunction2012 May 20 at 23:48:08.1 UTC
Greatest Eclipse2012 May 20 at 23:53:53.6 UTC
Greatest Duration2012 May 20 at 23:56:59.8 UTC
Equatorial Conjunction2012 May 21 at 00:00:16.3 UTC
Last Umbral Internal Contact2012 May 21 at 01:34:49.7 UTC
Last Central Line2012 May 21 at 01:37:34.4 UTC
Last Umbral External Contact2012 May 21 at 01:40:18.0 UTC
Last Penumbral External Contact2012 May 21 at 02:50:28.7 UTC

ParameterValue
Eclipse Magnitude0.94390
Eclipse Obscuration0.89094
Gamma0.48279
Sun Right Ascension03h52m43.0s
Sun Declination+20°13'15.1"
Sun Semi-Diameter15'48.1"
Sun Equatorial Horizontal Parallax08.7"
Moon Right Ascension03h52m30.7s
Moon Declination+20°39'06.3"
Moon Semi-Diameter14'43.3"
Moon Equatorial Horizontal Parallax0°54'01.7"
ΔT66.7 s

Eclipse season

This eclipse is part of an eclipse season, a period, roughly every six months, when eclipses occur. Only two eclipse seasons occur each year, and each season lasts about 35 days and repeats just short of six months later; thus two full eclipse seasons always occur each year. Either two or three eclipses happen each eclipse season. In the sequence below, each eclipse is separated by a fortnight.
May 20
Descending node
June 4
Ascending node
Annular solar eclipse
Solar Saros 128		Partial lunar eclipse
Lunar Saros 140

Related eclipses

Eclipses in 2012

An annular solar eclipse on May 20.

Metonic

Tzolkinex

Half-Saros

Tritos

Solar Saros 128

Inex

Triad