This month, the moon is closer to Earth than it’s ever been in this century — by about 300 kilometers.
That’s what Patrick Wiggins, NASA Solar System Ambassador to Utah, had to say about the supermoon scheduled to hit its apex on Monday night.
“Supermoon” is a term used by astrologers, not astronomers. It refers to a time when the moon is full and in the perigee side of its orbit, Wiggins said.
“When … you get a full moon and perigee at the same time, the astrologers call it a supermoon,” he said.
Each month, the moon follows an elliptical orbit around the earth. “Perigee” refers to the side of orbit that brings the moon closest to Earth.
According to NASA, a supermoon can appear as much as 14 percent bigger and 30 percent brighter than a regular full moon.
But to the human eye, the difference is hardly noticeable, Wiggins said.
“The change between this month and last month is so small, although it is measurable,” he said. “Personally, I get a little worried that people will go out expecting something that’s not there.”
The last time the moon passed by this close to Earth was in 1948. The next time it will come so close again will be on Nov. 25, 2034, according to NASA.
Supermoons — even ones as super as November 2016 — may not be the coolest or rarest phenomena in the sky. But that doesn’t mean it’s not fun to watch a full moon rise, Wiggins said.
“There is an optical illusion that makes the moon look a lot bigger than it really is called the full moon rising illusion,” he said. “Try to catch it [the moon] as it’s rising or setting and use your finger and thumb to measure how big it is. Then measure again a few hours later. A lot of people are surprised to find it’s the same size. It looks bigger when it’s down on the horizon.”
Although the illusion occurs regularly every month, it’s always neat to see — especially through binoculars or a telescope. In addition, howling can increase the joy of watching a full moon, Wiggins said.
“If you go out and see a full moon, be sure and howl. The moon will appreciate it,” he said.
For anyone who plans to watch the moon rise tonight, the moon should clear the Oquirrh Mountains around 7 p.m.