When the full moon rises Sunday night, it will be considered the biggest "supermoon" in 68 years. Weather permitting, it should be beautiful.
But it might not look much different than normal, to the naked eye.
The term "supermoon" is not an astronomical or technical one. It has come to refer to any full moon that occurs around the same time as lunar perigee, when the moon is closest to Earth in its elliptical orbit.
This year ends with three consecutive supermoons, and November's Full Beaver Moon is the biggest of them -- and the biggest of this century, so far. On Monday, the moon will swing closer to Earth than it has since 1948.
The centers of the moon and Earth will be 221,524 miles apart Monday morning, two and a half hours before the moon becomes full at 8:52 a.m., according to EarthSky.org.
According to NASA, supermoons can appear 14 percent bigger and 30 percent brighter than what are conversely known as micromoons, which occur when the moon is full at its farthest point from Earth in its orbit.
But NASA also explains how that doesn't necessarily mean the average skywatcher can tell the difference between a supermoon and any other full moon.
"A 30% difference in brightness can easily be masked by clouds or the competing glare of urban lights," NASA officials wrote in a blog post. "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."
Assuming skies are clear, Sunday night will likely be the best night to check out the supermoon. Even though the moon technically becomes full Monday, it will be at its closest to full, and to lunar perigee, as it sets at 6:35 a.m. Monday.
If you miss this supermoon, you will have to wait until Nov. 25, 2034, for a closer one.