NEW YORK—The last supermoon of the year will shine soon in December skies.
The moon’s orbit around the Earth isn’t a perfect circle so it gets nearer and farther as it swings around. When a full moon is closer to Earth in its orbit, a so-called supermoon happens. It makes the moon look up to 14 percent bigger and 30 percent brighter than the faintest moon of the year, according to NASA.
