What are supermoons?
A full moon happens when the moon (in its monthly orbit) is on the opposite side of Earth from the sun. A full supermoon happens when the full moon happens at – or near – the time the moon is closest to us in its elliptical orbit.
4 Full supermoons in 2024
Fred Espenak’s full supermoon table gives us these values – dates and moon distances – for full supermoons in 2024. Contrast these moon distances to the average moon distance of 238,900 miles (384,472 km).
Note: Fred’s dates are based on UTC time, so some supermoons may fall on the previous date your local time.
Aug 19: 224,917 miles (361,969 kilometers)
Sep 18: 222,131 miles (357,485 kilometers)
Oct 17: 222,055 miles (357,363 kilometers)
Nov 15: 224,853 miles (361,866 kilometers)
The August 19 full moon was the first of four supermoons in a row. And it was a seasonal blue moon, that’s because it’s the third of four full moons in a season.
The full supermoon of September 18, 2024, was a Super Harvest Moon. Plus, there was a partial lunar eclipse.
Then the full supermoon of October 17, 2024, was a Super Hunter’s Moon and the closest full supermoon for 2024.
By the way, 2025 will have three full supermoons in a row on October 7, November 5, and December 4. Then 2026 will start with a full supermoon on January 3, making it the 4th full supermoon in a row.
What are full supermoons?
It was the astrologer Richard Nolle who coined the term supermoon in 1979. He defines a supermoon as:
a new or full moon which occurs with the moon at or near (within 90% of) its closest approach to Earth in a given orbit.
However, different websites calculate supermoons differently. EarthSky uses supermoon dates as determined by astronomer Fred Espenak. Additionally, his method of calculating supermoons takes into account changes in the moon’s orbit during each lunar cycle.
Of course, full supermoons draw a lot of attention and are very popular.
But … do supermoons look brighter than ordinary full moons? Yes! By a noticeable amount. That’s because a supermoon exceeds the disk size of an average-sized moon by up to 8% and the brightness of an average-sized full moon by some 16%. And then, it exceeds the disk size of a micro-moon (a year’s most distant and therefore smallest full moon) up to 14% and the brightness of a micro-moon by some 30%. So, go outside on the night of a full supermoon. Even if you’re a casual observer of the moon, there’s a chance you’ll notice the supermoon is exceptionally bright!
By the way, before the term supermoon caught on, we in astronomy called these moons perigean full moons, or perigean new moons. No doubt about it, supermoon is catchier.
Earth’s oceans feel supermoons
At new moon or full moon, the sun, Earth, and moon align in space. The gravitational pull on Earth’s oceans is always greatest at such times. These are the spring tides, the highest (and lowest) tides coming twice each month (in contrast to the neap tides, when the variation between high and low tide is at its least, which happen around first and last quarter moon).
A new or full moon at perigee accentuates the spring tides. It creates what some call king tides, or exceptionally high tides, which are noticeable to those living along coastlines.
So, people living along the ocean shorelines might notice the variation in high and low tides for the coming months, around the dates of full moon.
One way or another, supermoons have an impact, even if it’s just enjoying the sight of a bright moon!
The exceptionally close August 2023 full supermoon
The supermoon of August 30-31, 2023, was the closest full supermoon last year when it was 222,043 miles (357,344 km) from Earth. And it also was a monthly Blue Moon. In astronomy, a Blue Moon is the second full moon in a calendar month. The next monthly Blue Moon is not until May 31, 2026. And the next time we’ll have a closer full supermoon is November 5, 2025, when the moon lies 221,817 miles (356,980 km) from Earth.
Read more: Want to see the brightest supermoon of 2023? Photos here
Bottom line: There are four full supermoons in a row in 2024. The fourth – an last – one for this year is November 15. It’s the Full Beaver Moon. Supermoons look brighter than ordinary full moons.
Read more: Super Harvest Moon and eclipse pics here!
Via AstroPixels: Moon at perigee and apogee: 2001 to 2100
Via AstroPixels: Phases of the moon: 2001 to 2100
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