Rare arrangement of Earth, moon and sun has not occurred since 1982 and will not happen again until 2033
The moon will loom large and turn coppery red on Sunday night as its closest approach to Earth coincides with a total lunar eclipse.
The rare arrangement of the Earth, moon and sun has not occurred since Survivor topped the charts with Eye of the Tiger in 1982, and the same orbital display will not happen again until 2033.
Because the moon follows an elliptical orbit, its average distance from the Earth changes, from as far away as 252,000 miles, to as near as 226,000 miles.
On Sunday evening, the moon will be at its closest, making it appear as a supermoon 14% larger in the sky than an average full moon. A one-penny coin is larger than a five-pence piece by the same percentage.
This time, the moon’s closest approach, or perigee, will coincide with a lunar eclipse late Sunday in North America and in the early hours of Monday morning over Europe, when the Earth moves in front of the sun and casts a shadow over the whole of the moon.
The moon will not be blotted out, but will instead turn dark red. Though no sunlight will fall directly on the moon, its surface will be illuminated by light rays that refract through Earth’s atmosphere. Red light will bend around the Earth and light up the moon, but blue light will be scattered and lost in the atmosphere.
“The moon usually turns a beautiful copper colour in a lunar eclipse. The light that shines on the moon is effectively the light of all the sunsets and sunrises on Earth,” said Marek Kukula, public astronomer at the Royal Observatory, Greenwich.
Weather permitting, the large red moon will be visible across the whole of Britain from 1.10am BST on Monday morning. At that moment, the Earth’s shadow will start to creep across the face of the full moon, causing it to dim and take on a yellowish hue. At 3.10am BST, the moon will be fully in Earth’s shadow, and for an hour and 12 minutes will turn a dark rusty red, or grey depending on surface conditions. The whole spectacle will be over by 6.25am BST Monday.
Lunar eclipses are visible from any spot where the moon appears above the horizon. The latest total lunar eclipse can be seen from west Africa, most of western Europe, most of North America and the whole of South America. In the US, the display will be visible late on Sunday afternoon and evening.
The eclipse will play out against the backdrop of the constellation of Pisces, and in the UK will appear beneath and left of the square of Pegasus. As the moon moves through the Earth’s shadow, it will head roughly due south to south-west in the sky.
On Wednesday, the Met Office predicted widepsread cloud cover over Britain for Sunday night and Monday morning, but conditions may change before the weekend.
This article was written by Ian Sample Science editor, for theguardian.com on Thursday 24th September 2015 09.38 Europe/Londonguardian.co.uk © Guardian News and Media Limited 2010