2017 Partial Lunar Eclipse Favors Africa, Asia, Australia and Europe

Summary: The 2017 partial lunar eclipse occurring Aug. 7/8 favors Africa, Asia, Australia and Europe as well as four of Earth’s five oceans.

graphic of view of Earth from moon near instant of greatest eclipse: SockPuppetForTomruen at English Wikipedia, Public Domain, via Wikimedia Commons

The 2017 partial lunar eclipse occurring Aug. 7/8 favors Africa, Asia, Australia and Europe as well as the world’s least populated continent of Antarctica and four (Atlantic, Indian, Pacific, Southern) of Earth’s five oceans.

The geographic regions of eclipse visibility exclude the North American continent. Eclipse visibility, albeit limited, over eastern Brazil qualifies the world’s largest Portuguese-speaking country as the only place on the South American continent falling within the viewing region.

Four main astronomical events track the progress of the August 2017 lunar eclipse. The penumbra, the weakest part of Earth’s shadow, frames the eclipse’s start and finish. Entry into and exit from the umbra, the shadow’s darkest and innermost part, frame the moon’s closest passage with the shadow’s axis.

The instant of first lunar contact with Earth’s penumbral shadow signals the start of August’s lunar eclipse. P1 is the identifier for the instant of first contact. NASA’s eclipse expert, retired astrophysicist Fred Espenak, gives Monday, Aug. 7, at 15:50:02 Coordinated Universal Time as the start time for 2017’s only partial lunar eclipse.

In the Central Pacific Ocean, the United States’ 50th state, Hawaii, falls within the penumbral entry’s viewing region. Entry begins Monday, Aug. 7, at 5:50 a.m. in Hawaii’s time zone, Hawaii-Aleutian Standard Time (HAST). Time and Date website recommends an observation spot with an unobstructed view of the west-southwest horizon. Hawaii loses direct visibility with moonset, which occurs at 6:05:22 a.m. HAST (16:05:22 UTC).

Contrastingly, Australia’s federal capital of Canberra, located about 5,218 miles (8,397 kilometers; 4,534 nautical miles) southwest of Hawaii’s capital of Honolulu, has complete visibility from start to finish. Penumbral entry begins early Tuesday morning, Aug. 8, at 1:50 a.m., because Australian Eastern Standard Time (AEST) is 10 hours ahead of Coordinated Universal Time.

Entry into the umbra occurs at 17:22:55 UTC. U1 is the identifier for the moon’s umbral entry.

During a partial lunar eclipse, the greatest eclipse takes place in the umbra. Greatest eclipse signifies the instant of closest lunar passage with the axis of Earth’s shadow. Greatest eclipse occurs at 18:20:27.7 UTC.

Exit from the umbra happens at 19:18:10 UTC. U4 is the identifier for the moon’s umbral exit.

Exit from the penumbra takes place at 20:50:56 UTC. P4 is the identifier for the moon’s penumbral exit.

The 2017 lunar eclipse claims a total duration of 5 hours 0 minutes 54 seconds. The partial portion of the eclipse, which concerns passage through the umbra, accounts for 1 hour 55 minutes 15 seconds of the total duration.

A partial lunar eclipse requires the coincidence of two celestial events. Firstly, the moon is in its full phase. Secondly, sun, Earth and moon exhibit a fairly straight line of alignment. Shadow casting by Earth onto the lunar surface necessitates alignment.

The moon turns full Monday, Aug. 7, at 18:10 UTC. Fullness, at 100 percent illumination of the Earth-facing lunar surface, happens about 10 minutes before the greatest eclipse event at 18:20:27.7 UTC. According to visualizations by Ernie Wright, lead visualizer at NASA’s Scientific Visualization Studio (SVS) at Goddard Space Flight Center (GSFC), the moon’s center-to-center distance from Earth will be 394,819 kilometers (245,329.153 miles) at 18:00 UTC, 10 minutes before official fullness.

The August 2017 partial lunar eclipse joins February’s penumbral lunar eclipse as the year’s only two lunar eclipses. An equal number of solar eclipses brings 2017’s eclipse total to four. February’s solar eclipse is annular while August’s solar eclipse is total.

The takeaway for the August 2017 partial lunar eclipse is the event’s expansive visibility over five of the world’s continents and four of Earth’s five oceans.

August 2017’s partial lunar eclipse data and geographic regions of visibility: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak, NASA GSFC Emeritus," via NASA Eclipse Web Site

Acknowledgment

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

Image credits:

graphic of view of Earth from moon near instant of greatest eclipse: SockPuppetForTomruen at English Wikipedia, Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Lunar_eclipse_from_moon-2017Aug07.png

August 2017’s partial lunar eclipse data and geographic regions of visibility: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak, NASA GSFC Emeritus," via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/LEplot/LEplot2001/LE2017Aug07P.pdf

For further information:

“August 7 / August 8, 2017 - Partial Lunar Eclipse.” Time And Date > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/lunar/2017-august-7

“Eclipses in Honolulu, Hawaii, USA.” Time And Date > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/in/usa/honolulu

Espenak, Fred. “Catalog of Lunar Eclipses: 2001 to 2100 (2001 CE to 2100 CE).” Eclipse Wise > Lunar Eclipses > Lunar Eclipse Catalog.
Available @ http://eclipsewise.com/lunar/LEcatalog/LE2001-2100.html

Espenak, Fred. “Partial Lunar Eclipse of 2017 Aug 07.” Eclipse Wise > Lunar Eclipses > 2001-2100.
Available @ http://eclipsewise.com/lunar/LEprime/2001-2100/LE2017Aug07Pprime.html

Espenak, Fred. “Six Millennium Catalog of Lunar Eclipses.” Eclipse Wise > Lunar Eclipses > Lunar Eclipse Catalog.
Available @ http://eclipsewise.com/lunar/LEcatalog/LEcatalog.html

“Event in UTC on Monday, August 7, 2017 at 3:50:02 pm.” Time And Date > Time Zones > World Clock > Event Time Announcer.
Available @ https://www.timeanddate.com/worldclock/fixedtime.html?p1=1440&iso=20170807T155002&low=4

Marriner, Derdriu. “February 2017 Annular Solar Eclipse Favors South Atlantic Ocean.” Earth and Space News. Wednesday, Feb. 15, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/02/february-2017-annular-solar-eclipse.html

Marriner, Derdriu. "February 2017 New Moon Blocks the Sun in Ring of Fire Annular Eclipse.” Earth and Space News. Wednesday, Feb. 22, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/02/february-2017-new-moon-blocks-sun-in.html

Marriner, Derdriu. “February 2017 Penumbral Lunar Eclipse Over Every Continent Except Australia.” Earth and Space News. Wednesday, Feb. 1, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/02/february-2017-penumbral-lunar-eclipse.html

Marriner, Derdriu. “February Full Moon Enters Earthly Penumbra for 2017’s First Lunar Eclipse.” Earth and Space News. Wednesday, Feb. 8, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/02/february-full-moon-enters-earthly.html

Smith, Ian Cameron. “Partial Lunar Eclipse of 7 Aug, 2017 AD.” Moon Blink > Hermit Eclipse > Lunar Eclipse List.
Available @ http://moonblink.info/Eclipse/eclipse/2017_08_07

“What Does the Magnitude of an Eclipse Mean?” Time And Date > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/magnitude.html

“What Is a Partial Lunar Eclipse?” Time And Date > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/partial-lunar-eclipse.html