Grab the binoculars, moon gazers. This Sunday, December 3, this month's full moon will be a "supermoon"!
So what is a supermoon?
A supermoon is defined as a full moon that occurs when the moon is within 90% of its closest distance to earth. There isn't any real astronomical significance to a supermoon, and we only recently began to take notice of it. The term was coined and defined in 1979 by an astrologer, but it is a time when the moon will appear a little bigger and a little brighter than normal.
Seeing it at all this time of the year can be a challenge. Luckily, we may see a break in the rainfall by the end of the weekend with some clearing, which should allow us to see the moon in its full glory.
Because the moon's orbit is elliptical instead of round, it has a point closest to the earth (perigee) and a point farthest from the Earth (apogee). This produces variations in the moons apparent size and brightness. The supermoon can give us a moon that is up to 30% brighter and 14% larger than when the moon is farthest from the Earth. These differences are most noticeable when the moon is full. And it is most striking at moonrise and moonset when the moon is near the horizon.
The moon will be very bright at moonrise on Saturday night, but here in the Northwest, it may be covered by clouds. The moonrise will be much more likely to be visible on Sunday night as clouds should be clearing out by then. Look for the moon to pop up above the northeast horizon about 4:59 p.m. Sunday.
If you snap any great pictures of the supermoon, please email them to firstname.lastname@example.org. The supermoon may not be scientific, but it will be pretty!