Don't forget tonight's Perigee Moon (18 September, 2024)

Full Moon September 18 19:33 ACST (FM 13:00 ACST, Perigee, 18th 22:30 pm -10h)	Full Moon February 24, 23:30 ACDST (apogee 26th +1d 2h)

This year we have two good Perigee Moons, September 18th and October 17. The differences are in Full Moon size are subtle, especially if you compare tonight's Full Moon with the October 17 Moon which is also a perigee Full Moon.  

It requires a keen eye and good memory to distinguish a perigee "super" Moon from more ordinary moons, the best contrast is with the apogee "mini" moon of February 24, even though this is not a good apogee Moon). 

That doesn't mean you shouldn't try though. Daniel Fischer has been able to see the difference, you can read his account and viewing tips here
http://earthsky.org/space/can-you-discern-supermoons-large-size-with-the-eye-an-observer-says-yes

Photographing them can be more rewarding. You can see images of perigee Moon and apogee Moon pairs from 21 Jan 2019 here and 10 August 2014 here.Tips for photographing them are here.

A full Moon at perigee has been called a "Super Moon", this is not an astronomical term (the astronomical term is perigee syzygy, but that doesn't trip off the tongue so nicely), but an astrological one first coined in 1979 (see here).

Still, it is a good excuse to get people out and looking at the Moon, which will be beautiful (although technically the Moon will be full at 1 pm this evening and perigee occurs at 10:30 pm later this evening, if it is clouded out you have another opportunity on October 17). Make sure you are not fooled by the Moon Illusion.