Eyes up tonight: There’s going to be a supermoon

Get out your cameras and binoculars: It’ll be mostly clear skies in Massachusetts Monday night for the supermoon. The moon will be brightest at 11:33 p.m. Eastern, according to the Old Farmer’s Almanac.

You may have seen the supermoon described as the “Full Pink Moon,” but don’t expect a particularly rosy satellite tonight. Each month’s full moon gets a nickname in the almanac derived from Native American and other traditional folklore. April’s is called the “Full Pink Moon” because its arrival typically corresponds with the blooms of Phlox subulata, a North American pink wildflower commonly called creeping phlox, moss phlox, or moss pink.

The term “supermoon,” coined by an astrologist in 1979, describes a new or full moon that occurs when the moon is near its perigee — the closest point to earth in its elliptical orbit — according to NASA’s website. It doesn’t have a precise astronomical definition, so this year could see either two, three, or four full supermoons, depending on who you ask. The next one, the “Full Flower Moon,” will be on May 26, and it’ll be the closest supermoon of the year.

Of course, new moons aren’t visible to the naked eye, so it’s full supermoons that get the most attention. They appear slightly larger and brighter in the sky than a typical full moon.

And it really is slightly. A supermoon is about 7 percent greater in diameter and 15 percent brighter than a typical full moon, and 14 percent greater in diameter and 30 percent brighter than a “micromoon,” which describes the full moon near its apogee, the farthest point away from Earth in its orbit.

Astronomers say it’s hard for inexperienced skygazers to actually spot a supermoon — the difference between a supermoon and a micromoon is about the same as a quarter and a nickel. If you look at the night sky and see that the moon does look particularly huge, it probably has little to do with the supermoon specifically.

The actual culprit is the moon illusion, which makes the moon appear subjectively larger when it’s near the horizon. It all happens in your brain, and while there are some possible explanations, scientists haven’t concretely figured out why it happens even though humans have observed it for millennia.

And by the way, those supermoon photos where the moon seems to loom like Jupiter in the sky? It’s clever camera trickery where photographers use long lenses to squash apparent distances. It’s the same effect that makes the dolly zoom work in films.

But at the (literal) end of the day, who cares? Whether the supermoon is overhyped and whether its size is an illusion made by the brain or the lens, the moon has entrenched itself into our collective imagination since humanity began looking up at the night sky.

Most of us probably don’t look at the moon enough. Tonight is as good a night as any.

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