Perigee and Apogee

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Christopher K.
Posts: 4376
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Perigee and Apogee

Post by Christopher K. » August 25th, 2014, 6:02 pm

Perigee is the point on the Moon's orbit at which it is closest to Earth. Apogee is the point on the Moon's orbit at which it is nearest to Earth. (The terms are used for orbits of artificial satellites as well.) As the Moon's orbit is not a perfect circle, perigee and apogee occur during each lunar cycle.

The 18 January APOD shows the rising of an apogee Full Moon that month; it was the smallest Full Moon of the last 1000 years.

18 January 2014 APOD:
http://apod.nasa.gov/apod/ap140118.html

Christopher K.
Posts: 4376
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Perigee and Apogee

Post by Christopher K. » October 8th, 2014, 3:21 am

Perigee occurred two days ago, and so this morning's lunar eclipse will be an exceptional view with a slightly closer Moon. Ben just arrived here at HRPO, and so there are five of us ready!

Christopher K.
Posts: 4376
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Perigee and Apogee

Post by Christopher K. » February 11th, 2015, 8:01 pm

This Friday night at 7:30pm, the Highland Road Park Observatory will present a lecture entitled "Journeys to the Moon". The talk will describe the different manners in which one can moongaze and the features one might expect to see using different magnifications. The talk has free admission and is aimed at a general adult audience (although most high schoolers should have no problem following it).

Christopher K.
Posts: 4376
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Perigee and Apogee

Post by Christopher K. » July 20th, 2015, 5:24 pm

Apogee will occur during the 6am Daylight hour tomorrow when the Moon is below the Baton Rouge horizon. Perigee will occur during the 5am Daylight hour on 2 August, when the waning gibbous Moon sits in a twilight sky (not too far from Neptune).

Christopher K.
Posts: 4376
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Perigee and Apogee

Post by Christopher K. » November 23rd, 2015, 9:26 pm

Perigee was at 2:07pm CST today. Tonight is an excellent night to view the waxing gibbous Moon. Try looking at the western limb to see any shadows and crater walls.

Christopher K.
Posts: 4376
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Perigee and Apogee

Post by Christopher K. » January 2nd, 2016, 4:17 pm

The last quarter Moon was last night at 11:30pm CST, and apogee occurs on 2 January. The waning crescent Moon can be well-viewed Monday morning from 3:16am to 5:36am. At that time the Moon will be in Libra, 2˚45' northeast of the A-class magnitude 4.5 star Lambda Virginis.

Christopher K.
Posts: 4376
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Perigee and Apogee

Post by Christopher K. » January 18th, 2016, 6:20 pm

Lunar perigee was on 14 January. The lunar perigee cycle and lunar phase cycle differ from each other by about forty-eight hours. Therefore, each perigee highlights the Moon with the terminator in a different location.

Christopher K.
Posts: 4376
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Perigee and Apogee

Post by Christopher K. » May 4th, 2016, 9:16 pm

Lunar perigee will be tomorrow at 11:13pm CDT. The Moon's distance will be ~357,974 kilometers. Unfortunately, New Moon is at 2:30pm on Friday! I believe a perigee Full Moon occurs in November.

Christopher K.
Posts: 4376
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Perigee and Apogee

Post by Christopher K. » March 2nd, 2017, 8:48 pm

Lunar perigee occurs at about 3am tomorrow morning. That means tonight and tomorrow night are very good opportunities to view the Moon, which will range in age from 4.8 days old to 6.0 days old when it reaches fifteen degrees altitude in the west Friday night around 10:15pm CST.

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