Is this full moon in March a super moon?

On March 28th, 20021year, there will be the fourth perigee full moon, which is also the fourth bigger and brighter moon this year. Critics are controversial about whether this full moon can be called super moon.

Photographer Peter lovins photographed the Super Moon in mutare. The super moon is not much bigger than other full moons, but it looks really bright! Thanks to photographer Pete!

On March 28th, 20021year, there will be the fourth perigee full moon, which is also the fourth bigger and brighter moon this year. Critics are controversial about whether this full moon can be called super moon.

The word super moon has already appeared in popular culture, but there is no official definition. The International Astronomical Union is a recognized organization that names and defines astronomical terms, but so far, the term super full moon has not been mentioned, and authoritative astronomers prefer to call it perigee full moon.

We collected comments about 202 1 super moon from three different sources.

First, according to TimeandDate.com, an outstanding website:

There are no official rules to judge how close or far it is to the moon to qualify as a super moon or a miniature moon. Different places have different definitions. Therefore, one place is classified as the full moon of the super moon, and another place is not necessarily the super moon.

Then TimeandDate gives its definition:

When the center of the moon is less than 360 thousand kilometers (about 223,694 miles) from the center of the earth, it can be counted as a full moon or a new moon.

Based on the definition of TimeandDate, only the full moons in April and May of 202 1 can be called super moons.

Our second source is Fred Espe Nack, an astronomer who studies everything related to solar eclipses. He listed the full moon on March 28th, 20021year as the super moon of perigee full moon. You can also find a table in this post, which is his list of super moons in 2 1 century, including four full-moon super moons in 202 1 year:

The third source is astrologer Richard Noel. No matter what you think or feel about astrology, Noel is the person who created the word "super moon" after all. In his list of super moons in 2 1 century, Richard Noel agrees with TimeandDate.com that there are only two full-moon super moons in 20021year:

Why is there such a big objection to the list of super moons? This stems from people's different definitions of super moon.

First of all, we can all agree that the judgment of the super moon is based on the perigee and apogee of the moon. Every month, the moon is closest to the earth at perigee and farthest from the earth at apogee.

At first, Richard? Noel defines the super moon like this:

A new moon or full moon that occurs when the moon is at or near (within 90%) the point closest to the ground in a given orbit.

If the new moon or full moon is at apogee, it is farthest from the nearest point of the earth; On the other hand, if the new moon or the full moon is at perigee, then the point closest to the ground is 100%. This is beyond dispute.

But is the description of "90%" a bit ambiguous? Then read on.

20 13 super moon was shot by Anthony Lynch of EarthSky, Dublin, Ireland.

Richard Noelle's figure of "90%" is calculated according to the perigee and apogee of the nearest moon to the Earth in 202 1 year. From Richard Knowler's list of all super moons in 2 1 century, it can be seen that the figure of "90%" is calculated according to the perigee and apogee of the moon in a year. Taking 202 1 as an example, according to the perigee and apogee data of this year, it can be calculated that any new moon or full moon less than 224,865 miles (about 36 1 0,885 kilometers) from the earth can be called super moon.

The following are the distances between the four closest satellites to the Earth in 20021year:

Full moon (March 28th, 202 1 year): 225,042 miles or 362 170 kilometers.

Full moon (April 27th, 202 1 year): 2222 12 miles or 3576 15 kilometers.

Full moon (May 26th, 202 1 year): 22 185 1 mile, or 357,462 kilometers.

Full moon (June 24th, 202 1 year): 224,652 miles, or 36 1558 kilometers.

In 202 1 year, the moon is farthest from the earth on May 1 1, 4065 12 km, and then it is closest to the earth on May 65438+February 4, 356794 km. The difference between the two is 49785 kilometers. Generally speaking, any new moon or full moon that is less than 36 1766 kilometers away from the earth can be regarded as "almost or 90% closest to the earth".

The longest distance between the earth and the moon in 202 1 year: 252595 miles (i.e. 4065 12 kilometers).

202 1: 22 1702 miles (356796 kilometers) is the shortest distance to the earth and the moon.

202 1 year maximum distance difference: 30893 miles (497 18 kilometers).

90% x 30893 miles (49718km) =27804 miles (44746km).

90% of the shortest distance between the earth and the moon = 252595 miles (406512km) -27804 miles (44746km) =22479 1 mile (361766km).

Therefore, according to the nearest perigee and farthest apogee in a year, it is calculated that "90% of the moon is closest to the earth". Measured from the centers of the Earth and the Moon, any new moon or full moon near the Earth of 22479 1 mile (36 1766 km) is counted as the super moon of 202 1 year.

Because the full moon on April 28th, 20021year can only reach 225,042 miles (362 170 kilometers) from the Earth, it can't be counted as the super moon on Richard Noelle's list. But we don't know why the full moon on June 24, 20021year didn't appear on his list.

20/kloc-the super moon photographed by yevgeny yorobe in July, 2004.

The definition of Espe Nack is based on 90% of perigee and apogee of lunar orbit. Ironically, Fred Espe Nack's list of super moons may have adhered to his definition more strictly than Richard Noelle himself (at least at the time of writing).

Richard Noel once again described the super moon as:

... a new full moon in the orbit between the moon and the earth, the closest to the earth (within 90% of the nearest distance).

If the established orbit can represent the current lunar orbit, then according to the latest apogee peak and the upcoming perigee value, the minimum near-earth distance of the full moon in March will be 95.9% of the minimum distance between the moon and the earth.

202 1 March 18 Distance: 252,434 miles (405,253 kilometers)

2021March 30th Distance: 223,886 miles (360,309 kilometers)

Distance difference: 28,548 miles (44,944 kilometers)

202 1 March 18 Distance: 252,434 miles (405,253 kilometers)

2021full moon on March 28th: 225042 miles (362170km).

Distance: 27,392 miles (43,083 kilometers)

The ratio of the distance between the apogee of the 202 1 March full moon and the upcoming perigee =27392/28548=0.959(95.9%).

According to our definition of a given orbit, we can find that the closest apogee of the moon to the earth on March 8/kloc-0 is 0%, and the closest perigee of the moon on March 30 100%.

In this case, the full moon in March will reach within 95.5% of its closest distance to the earth this month.

Fiona m donnelly's super cool Ontario moon rises. This photo is from the super moon in August of 20 14.

In March 20265438, the ratio of the distance of the super moon to the distance of perigee/apogee was +0.

Farthest location (202 1):252595 miles (4065 12 kilometers)

Apogee: (202 1): 252595 miles (4065 12 kilometers)

Perigee (202 1): 22 1702 miles (356,794 kilometers)

Distance difference: 30893 miles (49718km)

Apogee (202 1): 252595 miles (4065 12 kilometers)

Full moon in March (2021): 225,042 miles (362 170 kilometers)

Distance difference (2020): 27,553 miles (44,342 kilometers)

The ratio of the full moon in March to the apogee and perigee distance of that year =27553/30893=0.892(89.2%).

Comparison between super full moon (perigee full moon) and minimal full moon (apogee full moon). Image from Stefano Shapati/APOD.

Is the full moon in March a super moon? It depends on the perigee/apogee distance you choose. The distance between the perigee and apogee of the moon changes constantly throughout the year, so the limit distance of the super moon seems to depend on which perigee and apogee distance is used to calculate the nearest distance from the moon to the earth.

If we, like Noel, choose to define according to the nearest perigee and the farthest vertex in a year, then the definition of super moon will be narrowed; But as Espe Nack said, the definition of super moon is broader, based on the perigee and apogee of a given monthly orbit.

The size of the moon in our sky depends on its distance from the earth. The super moon (right) on March 1 19, 2065438 is compared with the conventional moon (left) on February 20 10. Image courtesy of Marco Langbroek of the Netherlands on Wikipedia.

We listed three different sources to determine whether the full moon on March 28th, 20021year should be called the super moon: TimeandDate.com, astronomer Fred Espe Nak and astrologer Richard Knowler. If the super moon is defined according to the nearest perigee and the farthest vertex in a year, then the full moon in March of 202 1 is not a super moon. If the super moon is defined according to the perigee and apogee of a given lunar orbit, it is a super moon. Whatever you say!

Author: Bruce Macclure

FY: Astronomy Volunteer Team

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