2017 Lunar Perigee Minimum Happens May 26 at 357,210 Kilometers

Summary: The 2017 lunar perigee minimum, with the moon at closest center-to-center distance to Earth, happens May 26 at 357,210 kilometers (221,960 miles).

Center-to-center distances log farthest (apogee) and nearest (perigee) points because the lunar orbit is elliptical, not circular; not-to-scale depiction of moon's orbit around Earth: NASA, Public Domain, via NASA Blogs

The 2017 lunar perigee minimum, with the moon at the year’s closest center-to-center distance from Earth, happens Friday, May 26, at 357,210 kilometers (221,900 miles).

According to Coordinated Universal Time (UTC), the world’s official time standard, the 2017 lunar perigee minimum takes place Friday at 01:23 (1:23 a.m. UTC). According to local time zones, the earliest date for the lunar event is Thursday, May 25. Thursday dates apply to time zones that are west of the primary time standard and that lag by two hours or more. Time zones that are east of the official time standard agree with UTC’s Friday date for the 2017 lunar perigee minimum.

May 26, 2017’s perigee claims double honors as both the month’s closest center-to-center distance and the year’s closest center-to-center distance. The yearly perigee is also known as proxigee.

May’s perigee of 357,210 kilometers exceeds the previous month’s perigee by 2,115 kilometers. Perigee happened at 16:18 UTC, Thursday, April 27, at a center-to-center distance of 359,325 kilometers (223,274.204 miles).

May’s perigee of 357,210 kilometers exceeds the next month’s perigee by 528 kilometers. Perigee happens at 10:49 UTC, Friday, June 23, at a center-to-center distance of 357,738 kilometers (222,288.088 miles).

Local time zones for continental North and South America claim Thursday, May 25, as the date of 2017’s lunar perigee minimum. Throughout the United States, 2017 proxigee occurs Thursday, May 25. In the time zones of the continental United States, 2017 proxigee happens May 25 as early as 6:23 p.m. Pacific Daylight Time (PDT) and as late as 9:23 p.m. Eastern Daylight Time (EDT).

Most of Alaska is covered by the Alaska Time Zone. Alaska mostly observes the 2017 lunar perigee minimum at 5:23 p.m. Alaska Daylight Time (AKDT), May 25.

The portion of Alaska’s Aleutian Islands west of 169 degrees 30 minutes west longitude lies within the Hawaii-Aleutian time zone. Unlikethe rest of Alaska, the western Aleutian Islands observe daylight savings time and, therefore, clocks 2017 proxigee at 4:23 p.m. Hawaii-Aleutian Daylight Time (HADT).

Hawaii does not impose daylight savings time. The United States’ 50th state registers the lunar event at 3:23 p.m. Hawaii-Aleutian Standard Time (HAST).

Many local time zones agree with Coordinated Universal Time that the latest date for the 2017 lunar perigee minimum is Friday, May 26. In Western Europe, Lisbon, Portugal registers the lunar event at the daylight savings time of 2:23 a.m. Western Europe Summer Time (WEST). On the Horn of Africa, the Federal Democratic Republic of Ethiopia’s capital, Addis Adaba, places 2017’s minimum proxigee at 4:23 a.m. Eastern Africa Time (EAT). The 2017 lunar perigee minimum happens Friday at 11:23 a.m. in the Australian federal capital of Canberra, according to Australian Eastern Standard Time (AEST) and also in Vladivostok in the Russian Far East, according to Vladivostok Time (VLAT). Kiritimati, also known as Christmas Island, in the northern Line Islands, clocks the lunar event Friday at 3:23 p.m. Line Islands Time (LINT).

The opposite extreme of the lunar perigee minimum value is the lunar perigee maximum value, which expresses the farthest point in the moon’s monthly center-to-center distance from Earth. The difference between the year’s minimum and maximum values is 12,646 kilometers. The 2017 lunar perigee maximum happens Wednesdayday, Sept. 13, at 16:04 UTC, at a center-to-center distance of 369,856 kilometers (229,817.864 miles).

The takeaway for the 2017 lunar perigee minimum of 357,210 kilometers that happens Friday, May 26, according to Coordinated Universal Time, is that the lunar event captures double honors as the minimum perigee value for both the month of May and for the entire year.

May 26, 2017’s lunar perigee minimum happens during moon’s new phase; New Moon visualization by Ernie Wright/NASA GSGC SVS: NASA/Goddard Space Flight Center Scientific Visualization Studio (SVS), Public Domain, via NASA SVS

Acknowledgment

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

Image credits:

Center-to-center distances log farthest (apogee) and nearest (perigee) points because the lunar orbit is elliptical, not circular; not-to-scale depiction of moon’s orbit around Earth: NASA, Public Domain, via NASA Blogs @ https://blogs.nasa.gov/Watch_the_Skies/2011/03/18/post_1300478717066/

May 26, 2017’s lunar perigee minimum happens during moon’s new phase; New Moon visualization by Ernie Wright/NASA GSGC SVS: NASA/Goddard Space Flight Center Scientific Visualization Studio (SVS), Public Domain, via NASA SVS @ http://svs.gsfc.nasa.gov/vis/a000000/a004000/a004000/

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 Friday, May 26, 2017 at 1:23:00 a.m.” Time And Date > Time Zones > World Clock > Event Time Announcer.
Available @ https://www.timeanddate.com/worldclock/fixedtime.html?p1=1440&iso=20170526T0123&low=4

Webb, Brian. “Coordinated Universal Time (UTC).” Space Archive. March 27, 2016.
Available @ http://www.spacearchive.info/utc.htm

Wright, Ernie. “Lunar Eclipses and the Moon’s Orbit.” NASA Scientific Visualization Studio. April 10, 2014.
Available @ https://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=4158

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