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Understanding the moon’s orbit around the earth:
As the moon orbits earth, its distance varies, sometimes coming closer and sometimes moving farther away. This happens because the Moon’s orbit is not a perfect circle but an ellipse. At its farthest point, called the apogee, the Moon is approximately 252,000 miles from Earth. At its nearest point, known as the perigee, it is about 226,000 miles away. The term “perigee” comes from Latin, meaning “near Earth.” When the Moon is within 10% of its closest approach to Earth, it is known as a supermoon. The below image is what the size difference looks like from a telescope.
The surprising origin of the term supermoon:
Did you know that the word “supermoon” didn’t exist before 1979? Scientifically, it’s not an official term. It was coined by astrologer Richard Nolle, who initially claimed that supermoons would align with severe weather and earthquakes. Although his prediction didn’t hold up, the term caught on and remains popular today. This photo is from Weeinthecity in League City shot Thursday night and submitted to Click2Pins.
But is a supermoon really super?
What most people notice during a supermoon is how much brighter it appears. In fact, a supermoon can be up to 30% brighter than the smallest full moon, making the night sky noticeably illuminated on a clear, calm evening.
But does it actually look bigger? While a supermoon is 14% larger than a typical full moon, the difference is subtle. Though side-by-side comparisons like the one below, might suggest a noticeable size change, to the naked eye, the difference is imperceptible. This has led many scientists to downplay the significance of supermoons. Astrophysicist Neil deGrasse Tyson even remarked that supermoons are “an embarrassment to everything else we call super.”
Putting the supermoon in perspective:
When discussing the moon’s distance from Earth, which spans hundreds of thousands of miles, and how it appears slightly larger or smaller depending on that distance, it can be difficult to visualize the difference from our perspective on the ground. To make this concept clearer, let’s use a relatable comparison: pizza.
Imagine the moon as a giant pizza. When it is at its farthest point from Earth, it measures 14 inches across. At its closest approach, it appears as a 14.1-inch pizza. That’s the extent of the change—just a tenth of an inch difference. Seen this way, the term “supermoon” might not seem so “super” after all.
Friday’s supermoon:
Our last supermoon of the year is on Friday night, with moonrise at 5:11 p.m. Every full moon appears larger at moonrise and moonset due to a phenomenon known as the “moon illusion.” This term refers to the optical illusion where the moon seems bigger when it is near the horizon, framed by terrestrial objects like buildings or trees. Although the moon remains the same size regardless of its position in the sky, the way our brains process visual information creates the perception that it is larger when it is close to the horizon.
I’d love to see your pictures of the supermoon. Please share them with us on Click2Pins!
