For the last time this year, a “supermoon” will rise in the night sky. Tuesday night, skywatchers can expect to see December’s full moon, the third and final supermoon of 2016.
A supermoon occurs when the moon is full and at its closest point to Earth in its elliptical orbit. Supermoons can shine as much as 30 percent brighter than a regular full moon.
This sighting also coincides with another celestial event: the Geminid meteor shower will take place at the same time, streaking across the sky as the supermoon shines bright. However, the meteors won’t be as easy to see tonight as they would have been in a darker sky.
The most recent supermoon was just last month, which was actually the closest the moon has been to Earth since 1948. The moon won’t get that close again in its orbit until Nov. 25, 2034.
“A supermoon, or perigee full moon, can be as much as 14 percent bigger and 30 percent brighter than an apogee full moon. However it’s not always easy to tell the difference. A 30 percent difference in brightness can easily be masked by clouds or the competing glare of urban lights. Also, there are no rulers floating in the sky to measure lunar diameters. Hanging high overhead with no reference points to provide a sense of scale, one full moon looks much like any other,” NASA wrote in an October blog post about the year’s three supermoons.
For those hoping to catch the supermoon at its biggest and brightest, NASA says it will reach its peak at 7:05 p.m. EST.
What about the Geminid meteor shower? The best time to check that out will be right before dawn on Wednesday morning.