Supermoon Tonight
Tonight it's a Saturday night. It's going to be beautiful tonight. Huge moons everywhere. I mean, sometimes the moon might seem big because it's low on the horizon and there's a tree in the way or something, but that just doesn't even hold a candle to what's going on tonight. It's what's called the perigee of the moon's elliptical orbit. That's an antonym of apogee. But I digress, the perigee is the point in the moon's orbit where it's closest to the earth. That's tonight, and it's pretty much going to be a full moon. Technically, it's not going to quite be a full moon here in the Northern Hemisphere, but what are ya gonna do?
This particular astronomical occasion, when the moon is both full and at it's perigee, only comes on once every twenty years or so. The last time it happened was in March of 1993. While the perigee is about 50km closer to the earth, it's still 356,577 km away. This does make a siginificant impact to the moon's visual appearance here on earth. The light reflecting from our lunar companion is going to be brighter, and the apparent visual size of the moon is going to be larger by 14%. I'm going to be howling extra loud tonight.
Take a look at this video, it explains everything. Then go outside tonight and take a look at the moon.
[via NASA]