'Supermoon' to give stargazers spectacular night sky show

Supermoon: Stargazers are in for a midnight treat - AP
Supermoon: Stargazers are in for a midnight treat - AP

A spectacular 'supermoon' will brighten up the night sky across the UK later today as it moves closer to Earth.

The full moon will appear 14 per cent bigger and 30 per cent brighter than usual to stargazers on Sunday evening.

Traditionally known as the Cold Moon, the full moon will be visible at 3:47pm this evening, with moonrise about 45 minutes later.

The impressive sight happens when a full moon is at the point in its orbit that brings it closest to Earth.

Tom Kerss, an astronomer at Royal Observatory Greenwich, said the supermoon will appear at its brightest at around midnight.

“This year's Cold Moon is closer to us than the average full moon this year; close enough to qualify as a supermoon, according to the widely accepted definition,” he said.  

“The moon will reach its highest point above the horizon at midnight local time. This is when, weather permitting, it will appear at its clearest and brightest.”

Graphic: What is a supermoon?

The full moon will be 222,761 miles from Earth, closer than its average 238,900 miles.

Mr Kerss told PA: “During moonrise and moonset, you might think the moon looks unusually large, but this is an illusion created in the mind when it appears close to the horizon.

“In fact, the change in the moon's apparent size throughout its orbit is imperceptible to the unaided eye.

“Nevertheless, the 'moon illusion' can be a dramatic effect, and with the moon rising so early, there will be ample opportunities to see its apparently huge face juxtaposed with the eastern skyline.”

The closest full moon of the whole 21st century will fall on December 6, 2052, when the full moon will be just 356,425 kilometres from our planet.

Supermoon  - Credit: Mark Blinch/The Canadian Press via AP
The moon rises over the CN Tower and skyline in Toronto Credit: Mark Blinch/The Canadian Press via AP

Super tides

When full or new moons are especially close to Earth, it leads to higher tides.

Tides are governed by the gravitational pull of the moon and, to a lesser extent, the sun.

Because the sun and moon go through different alignments, this affects the size of the tides.

There's lots of other moons too

Full moon: We all know what these are. They come around every month and light up the night at night.

Harvest moon: The full moon closest to the autumn equinox.

Black moon: Most experts agree that this refers to the second new moon in a calendar month. The last black moon was at the start of October 2016 and the next one is expected in 2019.

Blue moon: A phenomenon that occurs when there is a second full moon in one calendar month. Joe Rao from space.com explains: "A second full moon in a single calendar month is sometimes called a blue moon. A black moon is supposedly the flip side of a blue moon; the second new moon in a single calendar month."

Supermoon December 3 2017  - Credit: EPA
The event is the result of a full moon closer to the earth than usual Credit: EPA

The infrequent nature of this lunar event led to the phrase "once in a blue moon" to signify a rare occurrence. It does not actually mean the moon will be blue.

Blood moon: Also known as a supermoon lunar eclipse. It's when the shadow of Earth casts a reddish glow on the moon, the result of a rare combination of an eclipse with the closest full moon of the year.  There was one in September 2015, and before that in 1982 but the next one won't be until 2033. 

Strawberry moon: A rare event when there's a full moon on the same day as the summer solstice. It happened in June 2016 for the first time since 1967 when 17 hours of sunlight gave way to a bright moonlit sky.

Despite the name, the moon does appear pink or red. The romantic label was coined by the Algonquin tribes of North America who believed June’s full moon signalled the beginning of the strawberry picking season.