Stargazers are preparing for not one however two supermoons in August - culminating in a uncommon blue moon.

The supermoon phenomenon takes place when a full moon is close to its closest level to Earth, making it seem as much as 14% larger and 30% brighter in contrast with when it's furthest away.

People will get to see the primary on Tuesday night, 1 August, as the complete moon rises within the southeast from a mere 222,159 miles (357,530km) away.

It shall be even nearer on the evening of Wednesday 30 August, at a distance of 222,043 miles (357,344km) - and since it's the second full moon in the identical month, it is named a blue moon.

These figures evaluate with a distance of about 252,088 miles (405,696km) when the moon is at its furthest level from Earth.

How to see the supermoon

"Warm summer nights are the ideal time to watch the full moon rise in the eastern sky within minutes of sunset, and it happens twice in August," stated retired NASA astrophysicist Fred Espenak, who's nicknamed Mr Eclipse.

People utilizing binoculars or telescopes might even be capable of see options resembling lunar maria - the darkish plains shaped by historical volcanic lava flows - and rays emanating from lunar craters, Mr Espenak stated, supplied skies are clear.

"So long as there's not too much cloud, the full moon will be an unmistakable white orb in the sky," Royal Museums Greenwich states. "This is an efficient alternative to make use of a small telescope or a pair of binoculars to see the moon's detailed floor, and even strive taking a number of attention-grabbing moon pictures.

"However, you can see the moon perfectly well with just your eyes. Seeing moonrise just after sunset, or moonset just before sunrise, will be an impressive sight as it will appear enormous compared to the surrounding landscape."

Once in a blue moon

A full moon occurs as soon as in every lunar cycle, which lasts 29.5 days. As the moon travels in an elliptical path round, relatively than round, there are occasions when it's nearer than others.

The final time two full supermoons appeared in the identical month was in 2018 - and it will not occur once more till 2037, in accordance with Italian astronomer Gianluca Masi, founding father of the Virtual Telescope Project - therefore the phrase "once in a blue moon".

Mr Masi will present a stay webcast of Tuesday night's supermoon because it rises over the Coliseum in Rome.

"My plans are to capture the beauty of this... hopefully bringing the emotion of the show to our viewers," he stated. "The supermoon offers us a great opportunity to look up and discover the sky."

Writing on his web site, Mr Masi defined why the supermoon seems larger than regular.

"At night, the full moon is very bright, almost dazzling, compared to the darkness of the landscape, he said. "At its rise, the moon seems behind monuments and components of the panorama, producing the sensation that its disk is bigger than regular, however that is simply an optical phantasm, as a result of presence of these terrestrial components on the road of sight, giving grounds for comparability."

According to NASA, Mercury and Mars - which can be visible using only the naked eye - will appear in the sky as the supermoon rises on Tuesday.

Read more: Pictures from the July supermoon

This yr's first supermoon was in July, whereas the fourth and final shall be in September.

The motive for moons being given totally different names dates again years and pertains to the behaviour of the crops, animals, or climate.

According to the Old Farmer's Almanac, the August full moon is historically referred to as the sturgeon moon - due to the abundance of the fish in North America's Great Lakes in August, lots of of years in the past.