2017 Lunar Apogee Minimum Happens Aug. 30 at 404,307 Kilometers

Summary: The 2017 lunar apogee minimum, with the year’s lowest monthly apogee, happens Aug. 30 at 404,307 kilometers (251,224.723 miles).

map of Earth at instant of 2017 lunar apogee minimum, Wednesday, Aug. 30, at 11:25 UTC (7:25 a.m. Eastern Daylight Time): John Walker/Earth and Moon Viewer, Public Domain, via Fourmilab Switzerland

The 2017 lunar apogee minimum, which marks the lowest of the year’s monthly farthest center-to-center distances between Earth and its moon, happens Wednesday, Aug. 30, at 404,307 kilometers (251,224.723 miles).

According to Coordinated Universal Time (UTC), the world's official time standard, the 2017 lunar apogee minimum occurs Wednesday at 11:25 UTC (7:25 a.m. Eastern Daylight Time). Earth’s time zone conversions of Coordinated Universal Time to local times yield a trio of dates, from Tuesday, Aug. 29, through Thursday, Aug. 31, for local observances of the 2017 lunar apogee minimum.

Time zones that are ahead of Coordinated Universal Time by 12 hours 45 minutes or more experience the 2017 lunar apogee minimum on Thursday, Aug. 31. Chatham Islands, located east of New Zealand in the southwestern Pacific Ocean, lies in the Chatham Island Standard Time Zone (CHAST). During standard time, the archipelago is 12 hours 45 minutes ahead of Coordinated Universal Time. The 2017 lunar apogee minimum happens Thursday, Aug. 31, at 12:10 a.m. CHAST.

The 2017 lunar apogee minimum happens Tuesday, Aug. 29, in one time zone. Known as Anywhere on Earth (AoE), the time zone lags behind Coordinated Universal Time by 12 hours. Its identifier expresses the lag as UTC-12. The unincorporated, unorganized U.S. territories of Baker Island and Howland Island, which lie barely north of the equator in the central Pacific Ocean, clock time at 12 hours behind Coordinated Universal Time. The 2017 lunar apogee minimum happens Tuesday, Aug. 29, at 11:25 p.m. AoE, at these two uninhabited atolls.

The 2017 lunar apogee minimum of 404,307 kilometers is 1,627 kilometers less than the previous month’s apogee minimum. July’s apogee minimum happens Thursday, July 6, at 4:27 UTC (12:27 a.m. EDT), at a distance of 405,934 (252,235.694 miles).

The 2017 lunar apogee minimum of 404,307 kilometers is only 35 kilometers less than the next month’s apogee minimum. September’s apogee minimum takes place Wednesday, Sept. 27, at 6:49 UTC (2:49 a.m. EDT), at a distance of 404,342 kilometers (251,246.471 miles).

The 2017 lunar apogee minimum of 404,307 kilometers is 256 kilometers greater than the 21st century’s lunar apogee minimum of 404,051 kilometers (251,065.652 miles). The 21st century, which spans Monday, Jan. 1, 2001, to Friday, Dec. 31, 2100, achieves the lowest of its 100-year-span of lunar apogee minimum values at 4:42 UTC (12:42 a.m. EDT), Wednesday, July 26, 2069.

By the time of the 2017 lunar apogee minimum, the moon has already phased into its first quarter. The first quarter onset, which preceded achievement of the 2017 lunar apogee minimum by 20 hours 12 minutes, took over from the month’s waxing crescent at 8:13 UTC (4:13 a.m. EDT), Tuesday, Aug. 29.

The somewhat elliptical shape of the moon’s orbit accounts for the existence of apsides, which are points of extreme distances. The moon’s apsides (Ancient Greek ἁψίς, hapsís, “arch, vault”) are designated as apogee, for the farthest, or greatest, center-to-center distance between Earth and moon, and perigee, for the closest, or least, center-to-center distance.

The takeaway for the 2017 lunar apogee minimum that happens at 11:25 UTC, Wednesday, Aug. 30, at a center-to-center distance of 404,307 kilometers, is the milestone’s double qualifications as minimum apogee for both the month of August and for year 2017.

first quarter moon, Wednesday, Aug. 30, 11:00 UTC, 25 minutes before 2017 lunar apogee minimum: Ernie Wright/Dial-A-Moon, Public Domain, via NASA/Goddard Space Flight Center (GSFC) Scientific Visualization Studio (SVS)

Acknowledgment

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

Image credits:

map of Earth at instant of 2017 lunar apogee minimum, Wednesday, Aug. 30, at 11:25 UTC (7:25 a.m. Eastern Daylight Time): John Walker/Earth and Moon Viewer, Public Domain, via Fourmilab Switzerland @ https://www.fourmilab.ch/cgi-bin/Earth

quarter moon, Wednesday, Aug. 30, 11:00 UTC, 25 minutes before 2017 lunar apogee minimum: Ernie Wright/Dial-A-Moon, Public Domain, via NASA/Goddard Space Flight Center (GSFC) Scientific Visualization Studio (SVS) @ https://svs.gsfc.nasa.gov/4537

For further information:

Espenak, Fred. “Moon at Perigee and Apogee: 2001 to 2100 Greenwich Mean Time.” AstroPixels > Ephemeris > Moon.
Available @ http://astropixels.com/ephemeris/moon/moonperap2001.html

“Event in UTC on Wednesday, August 30, 2017 at 11:25:00 a.m.” Time And Date > Time Zones > World Clock > Event Time Announcer.
Available @ https://www.timeanddate.com/worldclock/fixedtime.html?p1=1440&iso=20170830T1125&low=4

Marriner, Derdriu. “2017 Lunar Perigee Minimum Happens May 26 at 357,210 Kilometers.” Earth and Space News. Wednesday, May 24, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/05/2017-lunar-perigee-minimum-happens-may.html

“Time Zone Abbreviations - Worldwide List.” Time And Date > Time Zones.
Available @ https://www.timeanddate.com/time/zones/

Wright, Ernie. “Moon Phase and Libration, 2013.” NASA Scientific Visualization Studios. Nov. 20, 2012.
Available @ http://svs.gsfc.nasa.gov/vis/a000000/a004000/a004000/