Monday, November 14, 2016
The Supermoon Period
A supermoon occurs when a full moon and lunar perigee occur at approximately the same time. There was one just before sunrise this morning, 14 Nov 2016. To find out when the next one will occur we can compute the average time between supermoons using two lunar periods.
So supermoons are spaced about 13½ calendar months apart and the next one should occur at the beginning of January 2018 followed by one about the middle of February 2019. The Lunarian gives the following circumstances for these events.
Lunar perigee 1 Jan 2018 21:48
Full Moon 2 Jan 2018 02:24
Lunar perigee 19 Feb 2019 09:02
Full moon 19 Feb 2019 15:53
The computed interval for the Supermoon Period seems to work quite well. One can expect some variation for this time interval due to the nonuniform motion of the Earth in its orbit.