Supermoon

The moon can look very big.

This is a supermoon. It happens when the moon is close to Earth. Because it is close, it looks larger. It also looks much brighter.

Some people say it can cause big waves. These waves can wash away sand on a beach. The moon also moves in a circle around us. Sometimes it is far away. When it is far, it is called a micromoon.

A supermoon is a wonderful sight to see.

A supermoon is a special full moon or new moon. It happens when the Moon is very close to Earth. This closest point in its orbit is called perigee.

When the Moon is at perigee, it looks bigger to us. It can look 14% larger than a regular moon. It also looks much brighter. A supermoon can be 30% brighter than a moon that is far away. This far point is called apogee.

Scientists use the term perigee-syzygy for this event. Syzygy is when the Sun, Earth, and Moon line up. Some people think supermoons cause earthquakes. However, scientists have found no link between them. They do say supermoons can affect the tides. This can cause bigger waves on beaches. These waves might wash away some sand.

Sometimes a supermoon happens during a total lunar eclipse. This is when Earth's shadow covers the Moon. The Moon may look red. People call this a Super Blood Moon.

A supermoon is a special sight in our night sky. It happens when a full moon or a new moon occurs near perigee. Perigee is the point where the Moon is closest to Earth in its orbit.

When this happens, the Moon looks slightly larger than usual to people on Earth. This event is also known as a perigee-syzygy. Syzygy is a word for when the Earth, Moon, and Sun are all lined up in a row. Because the Moon is closer, it can look 14% larger in diameter than a moon at its farthest point.

This special look happens because of how the Moon moves around our planet. The Moon does not travel in a perfect circle. Instead, its path is more like an oval. Because of this shape, the distance between the Earth and the Moon changes constantly. When the Moon is at its closest point, it also happens to be full or new. This makes the Moon appear much brighter to us. In fact, it can be 30% brighter than a moon at its farthest point, called apogee.

People have used different names for this for a long time. The term "supermoon" was created by an astrologer named Richard Nolle in 1979. He came up with the name while reading a paper by a scientist named Fergus Wood. While many people use the word supermoon, scientists often prefer the term perigee-syzygy. There is no single official definition for exactly how close the Moon must be. Different experts use different rules to decide if a moon earns the name.

Supermoons happen quite often throughout the year. Usually, three or four supermoons occur during each year. One very close full moon happened on November 14, 2016. It was the closest since January 26, 1948. The next time a full moon will be that close is November 25, 2034. Looking further ahead, the closest full supermoon of the 21st century will arrive on December 6, 2052.

Some people wonder if these big moons cause big changes on Earth. Some have claimed they cause earthquakes or volcanoes, but scientists have found no link. However, supermoons do affect the tides in our oceans. The pull of the Sun and Moon together makes the tides stronger during a full or new moon. This can lead to perigean spring tides. These larger tides can cause more beach erosion by washing sand away.

Sometimes, a supermoon happens during a total lunar eclipse. This creates a "Super Blood Moon" that looks large and reddish.

A supermoon is a celestial event that occurs when a full moon or a new moon coincides with perigee. Perigee is the specific point in the Moon's orbit where it is closest to the Earth.

Because the Moon is physically closer to our planet during this time, its apparent diameter looks slightly larger than usual in the sky. The technical astronomical name for this phenomenon is a perigee-syzygy. Syzygy refers to the straight-line alignment of the Earth, the Moon, and the Sun. This alignment happens during every full moon and every new moon. While the term "supermoon" is common in popular media, it is actually an astrological term rather than a precise scientific one.

The appearance of a supermoon is driven by the Moon's elliptical orbit. The Moon does not travel in a perfect circle around the Earth. Instead, its path is an oval shape, meaning the distance between the two bodies is always changing. When the Moon is at its farthest point, called apogee, it appears smaller. A full moon at perigee can appear roughly 14% larger in diameter than a moon at apogee. Additionally, the Moon appears much brighter when it is closer. Due to the inverse square law of light, a supermoon can be about 30% brighter than a moon at its farthest point. This brightness is directly proportional to the change in its perceived size.

There is no single, official scientific definition for what qualifies as a supermoon. The term was actually coined in 1979 by an astrologer named Richard Nolle. He created the name after reading a 1976 paper by a hydrologist named Fergus Wood. Nolle used a specific calculation based on 90% of the difference between the Moon's extreme distances during a solar year. Other experts have proposed different ways to define the event. For example, Fred Espenak uses Nolle's math but prefers the term "full Moon at perigee." Fergus Wood suggested a definition where the full or new moon must occur within 24 hours of perigee. He even coined the term "proxigee" for moons where the timing is within 10 hours.

Supermoons are relatively frequent events. In a typical year, there are 12 or 13 full moons, and usually three or four of them are classified as supermoons. The timing of these events follows a complex cycle. The distance to the full moon oscillates because of the difference between the synodic month and the anomalistic month. This cycle repeats roughly every 14 synodic months. In the Islamic lunar calendar, supermoons follow a specific cycle that moves through different months each year. Every 20 years, the timing shifts about one month earlier. This can result in two supermoons occurring in succession, such as in September and October of 2024.

History shows that some supermoons are much more extreme than others. The supermoon on November 14, 2016, was the closest full moon since January 26, 1948. It will not be surpassed in closeness until November 25, 2034. Looking even further into the future, the closest full supermoon of the 21st century will occur on December 6, 2052. Sometimes, a supermoon can even coincide with a total lunar eclipse. This rare combination creates what is known as a "Super Blood Moon." During a total lunar eclipse, the Earth passes between the Sun and the Moon. Earth's atmosphere scatters sunlight, filtering out blue light and casting a reddish hue on the Moon. This makes the supermoon appear both larger and a striking red or orange color.

Some people have speculated that supermoons cause major natural disasters like earthquakes or volcanic eruptions. However, scientists have found no evidence to support these claims. While some large earthquakes, such as those in New Zealand in 2016 or Tehran in 2020, have coincided with supermoons, there is no proven causal link. There is, however, a real effect on the Earth's oceans. The gravitational pull of the Sun and Moon is strongest during a full or new moon. When this happens at perigee, it creates "perigean spring tides." These are stronger tidal forces that can lead to measurable local effects.

These stronger tides, often called "kingtides," can impact coastal environments. Research involving 25 years of daily observations on sandy beaches shows that supermoons influence beach morphology. The larger tidal ranges produced by these events make beach erosion in the upper swashzone more likely. This means that when high waves occur during a supermoon, the erosion of the shoreline can be more severe. While the gravitational pull of a supermoon is weak in a global geophysical context, these local changes to the coast are a documented result of the Moon's proximity to Earth.