Super blue moon: Best photos from rare lunar event around the world

A rare super blue moon appeared over the UK overnight, treating stargazers to a spectacular display which won’t be repeated this decade.

A blue moon refers to the second full moon in a calendar month (a rare event in itself), while a super blue moon is where the moon is closer to Earth, appearing bigger.

The moon appears larger than usual, and it was expected to rise at around 8pm (BST) on Thursday to then set at around 6am (BST) the following day, but it shone on Wednesday night.

NASA says that the moon will appear full for three days around the peak – until Friday morning.

The best time to catch a glimpse is when your local conditions are best suited to a clear sky – low cloud cover, favourable weather, and no obstructions on the horizon – such as buildings or trees.

Super blue moon: Incredible pictures

What is a supermoon?

Supermoons are when the moon is closest in its orbit to the Earth, making it appear bigger and brighter than usual.

This month there will have been two supermoons – one on Tuesday, 1 August and another again on Wednesday, 30 August.

Dr Greg Brown, astronomer at Royal Observatory Greenwich, said: “August brings the joining of two rare events in astronomy: a blue moon and a supermoon.

“However, both events have somewhat complicated definitions, and none are universally accepted.

“The most common definition of a blue moon is that it is the second full moon in one calendar month.”

August is the first time in five years that two supermoons have appeared in the same month – which won’t happen again until 2037, astronomers believe.

Brown added: ”A supermoon, on the other hand, is a full moon that occurs when the moon is in the closest part of its orbit around the Earth, though exactly how close it needs to be to make it ‘super’ is up for debate.

“During this time, the Moon will appear a little bigger and brighter than it normally does, though the difference is hard to spot by eye.”

Supermoons (or perigean full moons) can be up to 14% bigger and 30% brighter than normal full moons – and are closer due to the Moon’s wonky orbit.

The term ‘supermoon’ was coined in 1979, with NASA saying: “When a full moon appears at perigee [its closest point to Earth] it is slightly brighter and larger than a regular full moon – and that's where we get a ‘supermoon’.”

Astronomer Professor Don Pollacco, from the department of physics at the University of Warwick, said: “One of the flukes of nature is that the apparent size of the moon can be very similar to that of the sun.

“This occurs because, while the moon is much smaller than the sun, it is much closer to the Earth.”

Adding that the moon has and elliptical orbit around the Earth, he continued: “Now that we understand the Moon’s orbit around the Earth we can talk about super moons.

“These occur when there is a full moon at the time when the moon is closest to the Earth.

“Consequently, the moon can look bigger (10-15%) and brighter (25-30%) than a normal full moon.”

This blue moon was even closer to Earth, at 222,043 miles away, making it appear bigger in the sky.

This compares with a distance of about 252,088 miles when the moon is at its furthest point from Earth.

What is a blue moon?

A blue moon is essentially the second full moon in a calendar month, which only happens roughly every two-and-a-half years, says Catherine Heymans, astronomer royal for Scotland.

Heymans said: "The astronomical definition of a blue moon is slighty more complicated. Basically it's roughly when there are two moons in a calendar month, which is happening in August

"It's a special time where you've got two in the same month."

This month, even more special is the fact the blue moon event is combined with two supermoons.