USA TODAY International Edition
Keep your eyes to the sky: A supermoon is coming!
Whether you call it super, snow or full, the biggest, brightest moon of the year is coming to a sky near you Tuesday.
A supermoon occurs when the moon is as close as it ever gets to Earth. On Tuesday, our moon will “only” be about 221,000 miles from Earth, which is about 17,000 miles closer than average.
The moon’s distance from the Earth changes because its orbit isn’t a circle. When the moon is closest to Earth, astronomers call it “perigee,” said Hanneke Weitering of Space.com. When the full moon coincides with perigee, you’ve got a supermoon, bigger and brighter than a typical full moon.
The term was coined in 1979 by astrologer Richard Nolle. It’s become an increasingly popular and media-friendly term in the decades since then.
The moon’s closeness to Earth, naturally, makes it look extra close and extra bright – up to 14 percent bigger and 30 percent brighter than a full moon at its farthest point from Earth, known as the apogee, NASA said.
Although this supermoon (and full moon) will officially occur Tuesday morning, you don’t have to wait for a specific moment to catch all the fun. The moon will appear plenty bright, big and mostly full for the entirety of Sunday, Monday and Tuesday nights – barring pesky clouds.
It’s especially big just as it rises above the horizon: This is called the “moon illusion” and it’s a way that your brain processes objects on the horizon, said Dean Regas, astronomer for the Cincinnati Observatory. “The moon isn’t actually bigger, it just looks like it,” he said.