Originally Posted by albertd:
“Although I realise that you were joking about my mistake, you are, in fact, more correct than it seems. There is a partial lunar eclipse in two weeks time, though not visible from the UK.”
It's because the lunar nodes, which are the two places where the Moon crosses the ecliptic in its orbit around the Earth, are currently lined up with the Sun, therefore after a solar eclipse the Moon takes 14-ish days to travel half way round its orbit and you get a lunar eclipse. Sometimes it has time to get all the way back round again and you get another solar eclipse (of some sort).
Then, after approximately 6 months during which the Earth goes about half way round its own orbit, the nodes are again lined up perfectly with the Sun and the sequence of two or three eclipses separated by two weeks happens again.
You can have anywhere from 4 to 7 eclipses of both kinds in any year, but two of the 4 minimum could be the very elusive penumbral lunar eclipses, as in 2016.
Check it out:
Eclipses in 2015
March 20: Total solar eclipse
April 4: Total lunar eclipse
September 13: Partial solar eclipse
September 28: Total lunar eclipse
Eclipses in 2016
March 9: Total solar eclipse
March 23: Penumbral lunar eclipse
September 1: Annular solar eclipse
September 16: penumbral lunar eclipse
So you do wait 6 months for one, then two turn up at once.
Although the penumbral lunars are almost indistinguishable as seen from Earth, on the Moon they represent a partial eclipse of the Sun by the Earth, and with the atmosphere glowing red and possibly night time city lighting (I don't know if it would be visible from that distance) must be quite spectacular. Probably worth the trip to see actually.