Partial Solar Eclipse Aug. 11 Is Third of Three 2018 Solar Eclipses

Summary: The partial solar eclipse Saturday, Aug. 11, is the third of three 2018 solar eclipses and closes 2018’s lineup of two lunar and three solar eclipses.

details of partial solar eclipse Saturday, Aug. 11, 2018: Fred Espenak, NASA/GSFC (Goddard Space Flight Center) Emeritus, via NASA Eclipse Web Site

The partial solar eclipse Saturday, Aug. 11, is the third of three 2018 solar eclipses, with all three happening as partial eclipses, as viewed from Earth, and also closes 2018’s eclipse quintet of two lunar and three solar eclipses.

August’s partial solar eclipse is the only 2018 solar eclipse that favors the Northern Hemisphere. Its solar predecessors, the partial solar eclipses of Thursday, Feb. 15, and Friday, July 13, occurred over Earth’s Southern Hemisphere.

The year’s third partial solar eclipse begins over North America and ends over Asia. The visibility region favors northernmost Europe and northeastern Asia. Bruce McClure, EarthSky Tonight’s lead writer, describes the year’s final eclipse as “. . . starting at sunrise in northeastern North America and ending at sunset along the Asian Pacific Coast.”

Oceanically, eclipse visibility takes in the Arctic Ocean at the top of the Northern Hemisphere. Visibility is also available to the northern reaches of the North Atlantic and minimally to the North Pacific Ocean. The western Pacific Sea of Okhotsk lies in the visibility path.

First contact between Earth’s surface and the moon’s penumbra announces the start of August’s partial solar eclipse. The penumbra is the lighter, outer region of the lunar shadow. On NASA’s Eclipse website, emeritus NASA astrophysicist Fred Espenak times first contact at 8:02:04.8 Universal Time (4:02 a.m. Eastern Daylight Time).

Time And Date website places start of the eclipse for Alert, northernmost Nunavut, Northern Canada, at 4:23 a.m. Eastern Daylight Time (08:23 UTC). Barentsburg, Svalbard, Norwegian Archipelago, experiences the eclipse’s start at 10:27 a.m. Central European Summer Time (08:27 UTC). Start time in Beijing, northeastern China, is 6:12 p.m. China Standard Time (10:12 UTC).

Greatest eclipse takes place at 09:46:15.0 UT (5:46 a.m. EDT; 11:46 a.m. CEST; 5:46 p.m. CST). For solar eclipses, greatest eclipse (GE) signifies the instant of closest passage to Earth’s center by the lunar shadow cone’s axis.

Greatest eclipse is expected to occur over the East Siberian Sea, a marginal sea of the Arctic Ocean. The location is between Wrangel Island and the Russian Far East’s Chukotka Autonomous Okrug.

Time And Date website places maximum eclipse in Alert, Nunavut, Canada, at 5:11 a.m. EDT (09:11 UTC). Barentsburg, Svalbard, Norway, experiences maximum eclipse at 11:16 a.m. CEST (09:16 UTC). Maximum eclipse in Beijing, China, is timed at 6:51 p.m. CST (10:51 UTC). Due to the sun’s closeness to the horizon, Time and Date recommends a Beijing location with free sight to the west-northwest.

August’s partial solar eclipse ends with last contact before Earth exits from the moon’s penumbra. Last contact occurs at 11:30:38.7 UT (7:30 a.m. EDT).

Time And Date website clocks eclipse ending in Alert, Nunavut, Canada, at 6 a.m. EDT (10:00 UTC). The partial eclipse ends in Barentsburg, Svalbard, Norway, at 12:06 p.m. CEST (10:06 UTC). Sunset at 7:16 p.m. CST (UTC) prevents Beijing, China, from witnessing the eclipse’s end at 7:28 p.m. CST (11:28 UTC).

August’s partial solar eclipse has the second longest duration of the year’s three partial solar eclipses. August’s solar eclipse lasted for approximately 3 hours 28 minutes 33 seconds. The Thursday, Feb. 15, partial solar eclipse claims longest duration of approximately 3 hours 51 minutes 17 seconds. The Friday, July 13, partial solar eclipse claims the shortest duration at approximately 2 hours 25 minutes 29 seconds.

August’s partial solar eclipse belongs to Saros cycle 155. The Saros cycle gathers similar eclipses into families, known as series. A Saros cycle endures for approximately 6,585.3 days (18 years 11 days 8 hours). Eclipses in the same Saros cycle occur at the same ascending or descending node, at about the same distance between Earth and moon.

Ascending and descending nodes indicate the two points of crossing Earth’s orbit by the moon’s orbit. The two nodes consider the approximately 5.1-degree tipping of the lunar orbit to Earth’s orbit around the sun.

August’s partial solar eclipse happens at the Saros 155-favored ascending node. The moon’s movement is southward from the node.

The end of August’s partial solar eclipse marks the closing of 2018’s eclipse quarter of two total lunar and three partial solar eclipses. The 21st century’s next solar eclipse occurs Sunday, Jan. 6, 2019, as another partial solar eclipse. January 2019’s partial solar eclipse favors Eastern Asia and the North Pacific Ocean.

The takeaways for the partial solar eclipse Saturday, Aug. 11, 2018, are that it occurs as the year’s only Northern Hemisphere solar eclipse, claims second longest duration of the year’s three partial solar eclipses and closes 2018’s eclipse quintet of two total lunar and three partial solar eclipses.

animation of partial solar eclipse Aug. 11, 2018: A.T. Sinclair/NASA via Wikimedia Commons

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

details of partial solar eclipse Saturday, Aug. 11, 2018: Fred Espenak, NASA/GSFC (Goddard Space Flight Center) Emeritus, via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/SEplot/SEplot2001/SE2018Aug11P.GIF

animation of partial solar eclipse Saturday, Aug. 11, 2018: A.T. Sinclair/NASA via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:SE2018Aug11P.gif

For further information:

“Accuracy of Eclipse Times.” TimeAndDate > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/accuracy.html

“August 11, 2018 -- Partial Solar Eclipse.” TimeAndDate > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/solar/2018-august-11

Espenak, Fred. “Eclipses During 2018.” EclipseWise > Solar Eclipses > Eclipses During 2018.
Available @ http://www.eclipsewise.com/oh/ec2018.html

Espenak, Fred. “Five Millennium Catalog of Solar Eclipses.” NASA Eclipse Web Site > Solar Eclipses.
Available @ https://eclipse.gsfc.nasa.gov/SEcat5/SE2001-2100.html

Espenak, Fred. “Glossary of Solar Eclipse Terms.” NASA Eclipse Web Site.
Available @ https://eclipse.gsfc.nasa.gov/help/SEglossary.html

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Available @ https://www.eclipsewise.com/solar/SEhelp/SEsarcatkey.html

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Available @ http://astropixels.com/ephemeris/moon/moonperap2001.html

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Available @ http://www.eclipsewise.com/solar/SEprime/2001-2100/SE2018Aug11Pprime.html

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Available @ https://eclipse.gsfc.nasa.gov/SEplot/SEplot2001/SE2018Aug11P.GIF

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Available @ http://www.eclipsewise.com/solar/SEcirc/2001-2100/SE2018Aug11Pcirc.html

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Available @ http://www.eclipsewise.com/solar/SEsaros/SEsaroscat.html

Marriner, Derdriu. “Crater Timings for Jan. 31, 2018, Total Lunar Eclipse Show Umbral Span.” Earth and Space News. Wednesday, Jan. 17, 2018.
Available @ https://earth-and-space-news.blogspot.com/2018/01/crater-timings-for-jan-31-2018-total.html

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Available @ https://earth-and-space-news.blogspot.com/2018/01/first-2018-eclipse-is-blue-moon-total.html

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Available @ https://earth-and-space-news.blogspot.com/2018/07/july-27-2018-total-lunar-eclipse.html

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Available @ https://earth-and-space-news.blogspot.com/2018/02/partial-solar-eclipse-feb-15-is-first.html

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Available @ https://earth-and-space-news.blogspot.com/2018/07/partial-solar-eclipse-july-13-is-second.html

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“Universal Time.” U.S. Naval Observatory > Astronomical Information Center > Time.
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