4 full supermoons in a row in 2023! 1st on July 2-3

4 full supermoons in a row in 2023

According to astrophysicist Fred Espenak – formerly at Goddard Space Flight Center and best known for his work on eclipse predictions – the full moon on the American night of July 2-3, 2023, is the first in a series of four full supermoons in a line.

Look on or around these dates:

July 2-3 overnight
August 1 morning or evening
August 30-31 at night
September 28-29 at night

Note: The above dates are best suited to the Americas, Europe and Africa. In other parts of the world, depending on where you live, some supermoons may fall on slightly different dates. Watch for the full moon around all these dates!

Bright full moon with a woman and a girl looking at it.
See photos from the EarthSky community. | Radu Anghel in Parjol, Romnia, took what he called “a family photo with the supermoon of July 13, 2022”. Thank you Radu! While supermoons don’t appear any bigger to the eye than other full moons, they do appear brighter!

What are supermoons?

A full moon occurs when the moon (in its monthly orbit) is on the opposite side of the Earth from the sun. A full supermoon occurs when the full moon occurs at the time the moon is closest to us in its elliptical orbit, or close to it. Fred Espenak’s table of full supermoons provides dates and distances for full supermoons in 2023. Contrast these lunar distances with the moon’s mean distance of 238,900 miles (384,472 km).

July 2-3: 224,895 miles (361,934 km)
August 1: 222,158 miles (357,530 km)
30-31 August: 222,043 miles (357,344 km)
September 28-29: 224,658 miles (361,552 km)

By the way, 2024 will also have four full supermoons in a row. They are August 19th, September 18th, October 17th and November 15th.

4 full supermoons: Diagram with Moon, Earth and Sun aligned and the orbits of Earth and Moon shown.
At a full moon, the sun, Earth, and moon align in space, in that order, with Earth at the center. The day side of the moon, its fully illuminated hemisphere, faces directly at us and that is why the moon looks full. Starting on the night of July 2-3, 2023, we will have 4 full supermoons in a row. Read about full supermoons below. Charted via John Jardine Goss/ EarthSky.

What are full supermoons?

It was astrologer Richard Nolle who coined the term supermoon in 1979. He defines a supermoon as:

a new or full moon that 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 determined by astronomer Fred Espenak. Additionally, his method for calculating supermoons takes into account changes in the moon’s orbit during each lunar cycle.

Naturally, full supermoons attract a lot of attention and are very popular.

But… they look like supermoons brighter compared to normal full moons? YES! By a substantial amount. This is 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 about 16%. And then, it exceeds the size of the disk of a micromoon (the most distant full moon and therefore smaller than a year) by up to 14% and the luminosity of a micromoon by about 30%. Then, go out on the night of a full supermoon. Even if you’re a casual moon watcher, there’s a chance you’ll notice that the supermoon is exceptionally bright!

By the way, before the deadline supermoon caught on, we in astronomy have called these moons perigean full moonsORnew moons perigee. No doubt about it, supermoon it’s more catchy.

Three full moons, a much larger one on the left and a noticeably smaller one on the right.
See photos from the EarthSky community. | Mandy Daniels of Derbyshire, UK made this composite image by comparing the apparent sizes of a full supermoon, mean full moon and micromoon. Thanks Mandi!

The full supermoon of August 2023 is exceptionally close

The August 30-31, 2023 supermoon will be the closest full supermoon this year when it is 222,043 miles (357,344 km) from Earth. And it’s also a monthly blue moon. In astronomy, a blue moon is the second full moon in a calendar month. By the way, the next monthly blue moon isn’t until May 31, 2026. And the next closest we get to a full supermoon is November 5, 2025, when the moon is 221,817 miles (356,980 km) from Earth.

Three large, bright full moons in a diagonal line.
See photos from the EarthSky community. | John Merriam in St Augustine, Florida captured the supermoon on July 13, 2022 and wrote, “Small time lapse of 3 shots before work to capture the full perigee Buck Moon over northeast Florida this morning.” Thanks, John! The July 2022 supermoon came within 222,089 miles (357,418 km) of Earth. The supermoon on August 30-31 this year will be 46 miles (74 km) closer to Earth.

Earth’s oceans feel like supermoons

At a new moon or full moon, the sun, Earth, and moon align in space. The gravitational pull on the Earth’s oceans is always greater at these times. These are spring tides, the highest (and lowest) tides that come twice a month (as opposed to low tides, when the variation between high and low tides is minimal, which occur around the first and last quarter moon).

A new or full moon at perigee accentuates spring tides. It creates what some call real tides, or exceptionally high tides, which are evident to those who live along coasts.

Hence, people living along ocean coasts might notice the variation of high and low tides for the next few months, around the dates of the full moon.

One way or another, supermoons have an impact, even if it’s just enjoying the sight of a bright moon!

2 diagrams: the sun, moon and earth and their positions during new moon and full moon.
About 3 or 4 times a year, or more often, a new or full moon coincides with the moon’s closest point to Earth, or perigee. There is usually only a small difference – typically a couple of inches (or centimeters) – between these “perigee spring tides” and normal tidal ranges. But, during these times, if a storm hits a coast, flooding can occur. Image via NOAA.

Bottom line: we will have four full supermoons in a row in 2023. The first is on the night of July 2-3. The closest – also a blue moon – will be August 30-31.

Via AstroPixels: Moon at Perigee and Apogee: 2001 to 2100 and AstroPixels: Phases of the Moon: 2001 to 2100

Read more: Four keys to understanding the phases of the moon

#full #supermoons #row #1st #July
Image Source : earthsky.org

Leave a Comment