Stargazers in the UK will be able to catch a glimpse of a “supermoon” this week, when the Earth’s natural satellite will appear at its biggest and brightest this year.
May’s full moon, also known as the “flower moon”, is expected to be visible at dawn on Wednesday (26 May), when the moon is at its closest point to Earth, although full illumination will not occur until later in the day.
What is a supermoon?
A supermoon occurs when the full moon is closest to the Earth, while a flower moon is the name given to the full moon in spring time, as it appears at the same time as blossoming flowers.
The moon is around 238,000 miles away from Earth on average, but during a supermoon it can be 221,000 mile away, making it appear much bigger and brighter than normal.
This month’s full moon will coincide with a total lunar eclipse in some parts of the world, although sadly this will not be visible from the UK.
A lunar eclipse occurs when the moon is fully obscured by the Earth’s shadow, lending it a reddish hue.
The change in colour occurs because light from the Sun is bent when it passes through the Earth’s atmosphere creating an effect known as “Rayleigh scattering”, which filters out bands of green and violet light in the atmosphere during an eclipse to leave just a red glow.
This phenomenon is where the term “blood moon” comes from.
The United States will have the best view of the eclipse, which will also be visible in Antarctica, Australia, Asia, and North and South America, but unfortunately it will not be seen from the UK.
Patricia Skelton, an astronomer at the Royal Observatory in Greenwich, explained: “People viewing the supermoon from the western US, western parts of South America, Australia or south-east Asia will witness the supermoon turn a shade of crimson red as a lunar eclipse will be taking place on the same day.
“This change in colour is not due to a physical change taking place on the moon, but simply because the moon will drift into the shadow of the Earth.
“The Earth’s atmosphere bends light from the sun and bathes the moon in a crimson red light.
“Although UK stargazers won’t be able to see the lunar eclipse, the supermoon is still worth a look.”
When to see the super flower moon
While the lunar eclipse will not be visible in the UK, it will be possible to spot the super flower moon later this week.
Ms Skelton said the best time to see the supermoon will be in the early hours of Wednesday (26 May) morning, or later in the evening on the same day, after sunset.
She said: “A supermoon happens when a full moon occurs at the same time, or close to the time, that the moon reaches its closest point to the Earth – a point called perigee.
“Perigee occurs at 2.51am on May 26, with full moon occurring at 12.14pm on the same day.
“The supermoon will rise in the east around half an hour after sunset and will be visible throughout the night.”
During this time, the Earth’s natural satellite will appear around 14 per cent bigger and 30 per cent brighter.
Ms Skelton added: “For the best views of the supermoon, wait for the moon to climb higher up into the sky.”