This is a good week for astrophiles, lunar fanatics, and werewolves, as the full Moon this week is going to be a special one: it will be a Mini-Moon.
On Thursday, the Moon will be at its apogee, its furthest point from Earth at more than 400,000 kilometers (249,000 miles) away. The apogee will be reached at 12:06 p.m. EDT (5:06 p.m. BST) on April 21, and the full Moon will be reached at 1:25 a.m. EDT (6:25 a.m. BST) on April 22.
The Mini-Moon, technically known as an apogee-syzygy of the Earth-Moon-Sun system (when all three objects align), happens because the Moon's rotation around our planet and its phase cycle don’t last the same amount time. People consider it a Mini-Moon if the apogee and full Moon happen within 24 hours of each other, and Mini-Moons happen about once a year.
Mini-Moons are not as well-known as Supermoons, which happen when a full Moon is at its closest approach to Earth (perigee). A Mini-Moon looks approximately 14 percent smaller and 25 to 30 percent dimmer than a Supermoon.
Comparison between the 2011 Supermoon and Mini-Moon by Ken_Lord via Flickr CC BY-NC-SA 2.0
April’s full Moon is traditionally called a Full Pink Moon, named by the Algonquin Indians as it is associated with moss pink, one of the first flowering plants of spring. The Moon will not actually change color, and no matter what you might have heard on the Internet in the past few days, it most definitely won’t turn green.
For people interested in both the Mini-Moon and its role in traditional agriculture, Slooh and The Old Farmer’s Almanac will have a live webcast about the Pink Mini-Moon on Thursday, April 21, at 8 p.m. EDT (1 a.m. BST).
You can go to Slooh.com to join and watch this live broadcast (embedded below), snap and share your own photos during the event, chat with audience members, interact with the hosts, and personally control Slooh’s telescopes.
The next Mini-Moon will be on June 9, 2017, but a rare occurrence will happen the year after when we will have a Mini-Moon featuring a lunar eclipse, which will occur on July 27, 2018.