It’s not just any full moon this week. We have a supermoon this coming Tuesday evening!

The moon will appear a little larger and brighter than average in the Butler heavens.

The term “supermoon” is relatively new, coined in 1979 by Richard Noell, an American astrologer.

Nothing against Mr. Noell, but there is a big difference between astrology and astronomy. Astrology is the study of how the movement of celestial bodies controls human behavior. Astronomy is the study of the nature of celestial bodies and their movements. You’ll never get an astronomer to come up with your horoscope!

A supermoon is any full moon that’s also close to the Earth. Let me explain. The moon’s 27.3 day orbit around the Earth is slightly elliptical, and because of that has a minimum distance from Earth called perigee, and a maximum distance from Earth called apogee. Meanwhile, the cycle of the moon’s phases (from new moon to new moon) is a little longer at 29.5 days. Because these cycles are not in sync, the full moon’s distance from Earth varies from month to month.

For a full moon to be officially considered a supermoon as defined by Noell, it has to be within 10 percent of perigee. For sure supermoons appear a little larger in the sky, but I think it’s a bit much to call it “super.” Like it or not, the term has become part of the culture.

Tuesday night’s full moon is the second of three supermoons this year, but it’s also the most super of the supermoons! It’s the closest full moon we have to Earth this year.

The closest the moon ever gets to the Earth at perigee is 221,429 miles, and on Tuesday night, the full moon will be just under 226,000 miles away.

Early Wednesday morning before the Supermoon sets, it’ll start turning into a “blood moon.” That’s a pop-culture term for a total lunar eclipse.

The moon will pass into Earth’s darkest shadow, known as the umbra and start disappearing.

Unfortunately timing is not on our side in Pennsylvania. Shortly after the moon enters Earth’s shadow, it’ll set below the horizon. Such is life blood moon lovers!

Not to worry though because we’ll have a partial lunar eclipse this coming Nov. 19 and a total lunar eclipse next May 16. In the meantime, next month will have a partial solar eclipse on June 10.

What to see early Wednesday morning are the giant planets Jupiter and Saturn, side by side in the low southeastern sky. They’ll be the brightest star-like objects in that part of the heavens.

With even a small telescope, you can see up to four of Jupiter’s moons that resemble tiny little stars that are constantly changing their positions around the planet. You may also see some of the cloud bands on Jupiter and Saturn’s fantastic ring system!

Mike Lynch is an amateur astronomer and retired broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul. He is the author of “Stars: a Month by Month Tour of the Constellations,” published by Adventure Publications and available at bookstores and adventurepublications.net. Contact him at mikewlynch@comcast.net.