Perigee moons occur when the full moon coincides with the closest point in the Moon’s orbit around Earth, resulting in a moon that is about 14% bigger and 30% brighter. This slight increase has led to the phenomenon gaining a nickname of ‘Supermoon’ though it won’t really look appreciably different. The image in the header gives a good representation of how ‘super’ it really will be.
The moon was actually at perigee last night, with the full moon happening tonight. There were perigee moons in July, August, and tonight’s event in September. There will be six perigee events next year, but three of them will be associated with new moons and won’t really be a spectacle. However, August, September, and October of 2015 will all have perigee full moons.
Tonight is also the Harvest Moon, which just means it is the full moon closest to the Autumnal Equinox on September 23rd.
If you aren’t able to head outside tonight to check out the moon for yourself, the folks over at Slooh Community Observatory will be broadcasting the event live from the Canary Islands with commentary from Geoff Fox and Slooh astronomer Bob Berman.
Tonight’s program will also include a special segment about Asteroid 2014 RC which safely passed by at about a tenth of the distance to the moon over the weekend. Use #SloohSupermoon on social media to join the conversation.
The event will begin at 9:30 pm EDT and you can check it out right here:
Don't miss out on any of the other sky watching events in 2014!