A plane is silhouetted against a so-called supermoon on July 12. Another of these celestial phenomena will grace our skies this evening, but astronomers say it will be even more spectacular than usual. (AP Photo/Mark J. Terrill)

Durban - If you take a look at the moon tonight it will be at its fullest, brightest and closest to Earth this year.

This phenomenon is known as a “supermoon”, when the moon appears to be 10 percent to 15 percent larger than usual.

The moon’s proximity to the Earth tonight will be a distance of 356 896km at perigee, the closest point, which will therefore make it the brightest and largest full moon of the year.

Also, the moon will be at its fullest at the same moment that it is closest to the Earth – something that will not happen again until 2034.

Nicola Loaring, outreach astronomer at the SA Astronomical Observatory, said that the average distance between the Earth and the moon was 384 400km.

However, because of the moon’s oval path of travel, the distance varied depending on where it was in orbit around the Earth.

At perigee, the moon was about 50 000km closer to the Earth than it was at its most distant point, she said.

“Full moons that occur when the moon is close to or at perigee are called supermoons and appear slightly larger or brighter than usual,” said Loaring.

“There has been one supermoon so far, in July, with another one expected in September. The supermoon will be visible from all over South Africa… and everyone should have a look at about 8.08pm local time because the moon will be at its closest point for the year.”

Logan Govender, a spokesman for the Durban centre of the Astronomical Society of Southern Africa, said that although supermoons occurred regularly this one was special.

“There are full moons every month but this supermoon is special because it will be at its fullest at the exact moment it is closest to the Earth,” he said.

“This is very important and what makes this occurrence different. Sometimes there is a full moon before it rises. You can call this a super supermoon.”

He said this would affect the tides but that it had no superstitious bearing.

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Sunday Tribune