First supermoon of the year illuminates the sky this Monday (3) – 7/3/2023 – Science

A few times a year, usually between three and four, the Moon comes closest to Earth, appearing bigger and brighter in the night sky. In these cases, it is called a supermoon.

Explaining it scientifically, the Moon’s orbit around the Earth is elliptical. In this way, the satellite sometimes passes closer (called perigee, on average 363,300 km) or farther (apogee, on average 405,500 km) from our planet.

According to astronomers, the supermoon appears up to 14% larger and 30% brighter than a normal Moon.

“This value we cannot take literally, it is around that. The angular size of the Moon in the sky at perigee is about 10% because of its elliptical orbit. This value can vary between 8% and 14% because it is not exact. So, we will have supermoons in which the Moon will appear larger than in others, because the distance will vary, although it is at perigee”, says astronomer Filipe Monteiro, postdoctoral fellow at the National Observatory.

The concept of a supermoon was created by the American astrologer Richard Nolle in 1979, who established that a full moon that occurs at perigee or 90% close to this point would receive the name “super”.

According to the National Observatory, since the year 2000, the day on which the supermoon came closest to Earth was on November 14, 2016, when it was 356,509 kilometers away from the planet. The prediction is that such a close passage will occur again on December 24, 2026, when the Moon will be 356,650 kilometers from Earth.

NASA says that high and low tides are influenced by the supermoon. “The extremes are greater due to the difference in the Moon’s gravitational pull along the Earth’s diameter. When the Moon is close, the Earth’s diameter is a slightly larger fraction of the separation between the Earth and the Moon. This means that the gravitational attraction of the Moon in the oceans (and in the Earth’s crust) has a greater difference between the point on Earth closest to the center of the Moon and the point on Earth diametrically opposite it (the antipode). This increases the effects of the tides”, says the agency on its official website.