In recent years, the name “supermoon” has appeared very often in the press, making many people think that it is an extremely attractive phenomenon. However, in reality, this is not necessarily the case. Let’s find out what this phenomenon really is and look at the most frequently asked questions about it.
What is a supermoon?
The super moon is full moon Or new Moon At this point near the field (perigee, the closest position to Earth in the orbit of an Earth-orbiting body, in this case the Moon), or approximately 90% of the perigee distance from Earth.
Currently there is no unified convention yet on what is “90% close”, some sources take the figure of 359,000 km, others 360,000 km, and this article will use the figure given by the author himself. term calculates: 361,554.9 kilometer. This means that if a full moon or new moon is at least this distance from Earth, it will be considered a supermoon.
Seen from Earth, the full Moon at perigee will have a larger apparent diameter than the normal Moon.
The Moon’s orbit around Earth is elliptical, so there will be times when the Moon reaches its perigee or apogee. Source: The doubled wolf
The new moon at perigee cannot be observed because it occurs during the day, although astrologers classify it as a supermoon and may be useful to those interested in the signs of the zodiac, but for astronomers this phenomenon is not of much value because it cannot be observed.
Where does the name “supermoon” come from?
The term “supermoon” does not belong to astronomy, but it originated in the astrology of an astrologer named Richard Nolle – the first person to coin the word “supermoon” and define the full moon. and the new moon is a supermoon when the Moon is at or near (90%) perigee.
Supermoon in Novogrudok, Belarus, 2015. Author: Sergei Grits/AP
The term “supermoon” is not often used in astronomy, but scientists instead call it “alignment of the Earth-Moon-Sun system at perigee” (perigee syzygy) or “Full Moon/New Moon at perigee” .
However, with the development of media and society, the term “super moon” has become popular and used by many people. Obviously, it’s easier to talk about a “supermoon” than to use obscure scientific terms like “alignment of the Earth-Moon-Sun system at perigee.” It’s no wonder then that the term “supermoon” has become popular.
How much bigger and brighter is a supermoon than a normal full moon?
The full moon at perigee, or supermoon, is about 14% larger and about 30% brighter than the full moon at apogee (farthest point). A supermoon, compared to an average full moon, is only about 7% larger and about 16% brighter.
Compare the size of the full moon at Perigee and Apogee. Source: TerreCiel
When you appear in the press, you may hear some sources exaggerate the size and brightness of the supermoon. Although we encourage you to observe the Moon, eclipses and other astronomical phenomena, it must be said that the supermoon in the sky is not very different from other full moons.
How many supermoons are there each year?
Each year, there are 12 to 13 full moons (or new moons), and of these, 3 to 4 are generally considered supermoons.
The supermoon of November 14, 2016 is considered the closest full moon to Earth since 1948, and it will not be until November 25, 2034 that this record will be broken by another supermoon. The closest super full moon to Earth in the 21st century will be on December 6, 2052.
The Super Moon of January 31, 2018 coincided with a total lunar eclipse. Author: Sergio Garcia Rill
Sometimes a supermoon coincides with a total lunar eclipse. The last time was in January 2018 and the next time will be in January 2019 (not visible in Vietnam).
Does a supermoon affect tides on Earth?
The influence of the Sun and Moon on Earth’s oceans is greatest when it is a full or new moon. The tidal force exerted by the perigee supermoon on the oceans will be a little stronger than a normal full moon or new moon, but because gravity is relatively weak, it will only raise the tide 2 feet to 5 cm.
Author: Robin Ohia via Flickr
Is the super moon linked to natural disasters?
You may also hear hype that a supermoon can increase the risk of events such as earthquakes, volcanic eruptions or tsunamis. But in reality, there is no evidence confirming that the supermoon contributes to these phenomena.
Super Moon 2014 in Los Angeles. Author: Andy Lesniak
Speculation about this link arose when media cited evidence from the 2004 Indian Ocean earthquake and tsunami; 2011 Tōhoku earthquake and tsunami, Japan; and a magnitude 7.5 earthquake about 15 km northeast of Culverden, New Zealand, on November 14, 2016. Since then, no disaster has been scientifically proven to be linked to the supermoon.
Why does the supermoon still seem… small?
Supermoons are completely normal. The name “supermoon” simply refers to a full moon at perigee. Any full moon low just above the horizon is impressive, but once it’s high in the sky, size-wise it’s not easy to see the difference with a full moon at apogee .
The Moon appears larger at sunrise than when it is high in the sky, partly because when it is near the horizon it is compared to houses and mountains. Source: CNN
It can be very impressive when the Moon is seen near the horizon, and it’s worth going out to admire it. However, when the Moon is high in the sky, there are no buildings, trees, or hills to compare it to, and so its apparent size does not appear much different from a normal full moon. The apparent size difference from a normal full moon is negligible and much harder to detect.
Epilogue: Far from the rumors in the press, the Super Moon is just a normal phenomenon, nothing very different. Speaking of this phenomenon, we just want readers to take this opportunity to take some time to relax and look at the MOON, so as not to forget the beauty of nature.
SUPER MOON IN 2019
In 2019, there will be three super full moons:
On January 21, 2019, the Moon was 357,715 km from Earth
On February 19, 2019, the Moon was 356,846 km from Earth
On March 21, 2019, the Moon was 360,772 km from Earth
Read more: How to take impressive Super Moon photos?
Short translation of: Eclipsegeeks & Earthsky