Stargazers will be treated to a rare lunar event if they look to the skies this weekend.
Experts say a ‘blue micromoon’ will appear on Saturday evening – and people in the UK will be able to see it.
This unusual phenomenon refers to the second full moon that appears in the same calendar month, giving stargazers an extra chance to enjoy one of the night sky’s most impressive sights.
It is rare because a full moon usually occurs once every 29.5 days, working out at around once per month.
But this one is especially significant because the moon will also be at its furthest point from Earth – an event which won’t happen again until 2053.
‘A blue moon is the second full moon within a single calendar month, something that happens only every two to three years,’ Alan Jones, from 365 Astronomy, said. ‘Despite the name, the moon will not actually appear blue.
‘This year’s event is also a micromoon, meaning the moon is near the furthest point in its orbit from Earth.
‘It may appear slightly smaller and dimmer than usual, although the difference is subtle.’
The unusual phenomenon refers to the second full moon that appears in the same calendar month
When to see the blue micromoon
The blue micromoon will reach peak illumination on Sunday.
However, the best time for stargazers will be on Saturday evening when the moon rises shortly after sunset and stays visible throughout the night, Mr Jones explained.
‘It will sit relatively low in the southern sky, so choosing a spot with clear views of the eastern and southern horizon, away from tall buildings and trees, will provide the best experience,’ he added.
Why the moon can appear orange or red
As the moon rises or sets near the horizon it can take on orange, amber or reddish tones.
This is because Earth’s atmosphere scatters shorter blue wavelengths of light.
‘The well-known ‘moon illusion’ can also make the moon appear larger when it is low in the sky, even though its actual size does not change,’ Mr Jones added.
A nearly full moon rising behind the US Capitol Building at dusk on Thursday this week, ahead of the blue micromoon this weekend
While it will be visible with the naked eye, using binoculars can help enhance the view and reveal crater regions in more detail
Is the blue moon worth observing?
Mr Jones said full moons are excellent targets for casual observers, families and beginner astronomers.
‘A blue moon also carries a sense of rarity reflected in the phrase ‘once in a blue moon’,’ he added.
‘While not exceptionally rare astronomically, these events still capture people’s imagination and encourage more of us to look up at the night sky.’
Tips for viewing and photographing the moon
The moon will be visible with the naked eye.
However, using binoculars can help enhance the view and reveal crater regions in more detail.
‘Smartphones can also capture impressive images when mounted on a tripod and used with manual exposure settings,’ Mr Jones said.
In 2024 a full ‘supermoon’ rose over London’s skyline, appearing 14 per cent bigger and 30 per cent brighter than other full moons
He added: ‘For dramatic moonrise photos, include buildings, trees or landscape features in the foreground to help show the moon’s scale against the horizon.
‘For closer lunar photography, a telescope with an aperture of around 80mm or more will provide crisp detail.
‘Smart telescopes such as the Dwarf 3, Seestar S30 or S50, eVscope 2 and Vespera II are also excellent beginner-friendly options for capturing detailed lunar images.’
The moon will also look full in the days before and after the peak, giving stargazers an extra chance to spot it.
The phases of the moon
Like Earth, the Moon has a day side and a night side, which change as the Moon rotates.
The Sun always illuminates half of the Moon while the other half remains dark, but how much we are able to see of that illuminated half changes as the Moon travels through its orbit.
In the Northern Hemisphere, the phases of the moon are:
1. New Moon
This is the invisible phase of the Moon, with the illuminated side of the Moon facing the Sun and the night side facing Earth.
2. Waxing crescent
This silver sliver of a Moon occurs when the illuminated half of the Moon faces mostly away from Earth, with only a tiny portion visible to us from our planet.
3. First Quarter
The Moon is now a quarter of the way through its monthly journey and you see half of its illuminated side.
4. Waxing Gibbous
Now most of the Moon’s dayside has come into view, and the Moon appears brighter in the sky.
5. Full Moon
This is as close as we come to seeing the Sun’s illumination of the entire day side of the Moon.
6. Waning Gibbous
As the Moon begins its journey back toward the Sun, the opposite side of the Moon now reflects the Moon’s light.
7. Last Quarter
The Moon looks like it’s half illuminated from the perspective of Earth, but really you’re seeing half of the half of the Moon that’s illuminated by the Sun ― or a quarter.
8. Waning Crescent
The Moon is nearly back to the point in its orbit where its dayside directly faces the Sun, and all that we see from our perspective is a thin curve.
