If the full moon this month seems larger and brighter than normal, it won’t just be your imagination.
July’s full moon, known as the Buck Moon, will rise on Wednesday, July 13. What’s cool is that it will be a supermoon — appearing 14 percent larger and 30 percent brighter than other full moons.
Why It’s A ‘Buck Moon’
The Old Farmer’s Almanac uses moon names from a number of places, including Native American, Colonial American, and European sources.
Male deer, bucks, shed and regrow their antlers each year. The full moon in July gets its Buck Moon name from Native American sources because this is the time of the year when bucks’ antlers are growing quickly.
Why It’s Also A Supermoon
The moon’s orbit around Earth is elliptical, rather than circular. Although the distance between the moon and Earth varies throughout the month and even the year, the average distance is approximately 238,855 miles, according to NASA.
Since the moon has an elliptical orbit, there are times when it is closer to Earth than others. The point in the moon’s orbit when it is closest to Earth is called the perigee. When the moon is full and it reaches that point, it’s called a supermoon.
There is no official definition stipulating how close the moon must be to Earth to be considered a supermoon. Astrologer Richard Nolle first used the term “supermoon” in 1979, and in his definition, Nolle explained that a full moon or new moon is a supermoon when it’s within 90 percent of its closest point to Earth, according to EarthSky.
While the average distance from Earth to the moon is 238,855 miles, on July 13, however, the moon will be 222,089 miles from Earth, making it a supermoon, EarthSky explains. What’s more, July’s supermoon will be the closest to Earth of all four supermoons this year.
How To See The Buck Supermoon
July’s Buck Supermoon will reach peak illumination at 2:37 p.m. Eastern Standard Time, on Wednesday, July 13, according to Time and Date. However, the moon will be below the horizon at that time.
Instead, full moons rise around sunset and set around sunrise. You can determine the exact time of moonrise in your area here.
You’ll want to make plans to see the Buck Supermoon when it’s just above the horizon because that’s when it will appear largest due to what’s called the “moon illusion.”
The moon, of course, doesn’t change size, but the moon illusion tricks our brains into thinking it sometimes appears larger or smaller. Here’s why: When the moon is high in the sky, it appears small due to the vast scope of the surrounding sky, NASA explains.
The flip side of the coin is that when the moon is just above the horizon, our brains compare the moon’s size to other objects on the skyline, such as trees, buildings, or water towers. Compared to those objects, the moon, of course, seems absolutely massive.
Finally, since the moon illusion occurs when the moon is low in the sky, the best place to see the Buck Supermoon will be somewhere with an unobstructed view of the horizon. Large fields, parking lots, and other places that don’t have trees or buildings blocking the horizon will be good places to see the Buck Supermoon at its largest and brightest.
While you’re thinking about the Buck Supermoon, be sure to read all of our stargazing content, including: