How to see the full Buck Moon 2021 in the UK tonight
When can you see the full Moon? And how can you take an Instagram-ready photo of it?
Full Moons come around once a month, but they are still an astronomical event worth viewing. For a few short nights, the Moon will be big and bright, making it one of the easiest things for an amateur astronomer to appreciate.
This month's is called the Buck Moon, although in the UK it's usually called the Hay Moon.
When exactly can you see this month's full Moon? What features should you look out for on its surface? And, most importantly, how can you take an Instagram-ready photo of it?
We put all of these to Dr Darren Baskill, an astronomer and astrophotographer based at the University of Sussex. For more stargazing tips, check out our astronomy for beginners guide, and meteor shower UK calendar.
When is the Buck Moon 2021?
Look out for 2021's next full Moon on 24 July. In the UK, it will be completely full at 3:36am on Saturday morning. Don't worry, you don't have to stay up that late to see it.
"Strictly speaking, the full Moon occurs at a very specific moment in time – down to the second! – when the Moon is directly opposite the Sun in the sky," says Baskill. "But to our eyes, the Moon will look full, or almost-full, for two or three days either side of the exact moment that the full Moon occurs."
How often do full Moons happen?
The lunar cycle is roughly 29.5 days long, which means we usually get one full Moon a month. On rare occasions, we get two full Moons in the same month, although that won't happen again until August 2023.
What features of the Moon can you see when it’s full?
The full Moon is a beautiful sight, and as you stare up at it, you may wonder exactly what you're seeing on the lunar surface.
"While most of the Moon is heavily cratered, around the full Moon we can also see smooth areas called 'seas' that make up a third of the side that permanent faces us. These areas were flooded with molten lava some four billion years ago, which quickly cooled leaving the smooth appearance that we see today," says Baskill.
"The large crater called Tycho can also be seen by eye towards the bottom of the Moon as we observe it, with rays of ejected dust and debris emanating that cover a good portion of the entire Moon, indicating just how violent this impact was that occurred a mere 108 million years ago.
"That said, many features are actually less impressive at full Moon. At other phases, sunlight shines across the Moon, which can bring out some stunning views as crater walls many kilometre high cast dramatic shadows – a stunning sight in either a small telescope or binoculars. Unfortunately, we can’t see these shadows during full Moon."
What else will be visible in the sky in the UK during the full Moon?
Stargazing is tricky when there's a full Moon. "Due to the full Moon being so bright, the light from the Moon drowns out our view of all but the brightest objects in the night sky," says Baskill. "Fortunately, some planets are so bright that we can easily see them by eye, even in a moonlit sky.
"As the Moon orbits around the Earth, it moves across the sky, moving to the left by about the size of your fist at arm’s length every 24 hours. So, while on the Saturday evening of the 24th July, the Moon will be just below the planet Saturn, on the following evening it will have moved to the left a bit to be by the bright planet Jupiter. Over the weekend, all three of them will be rising together in the east at around 10:30pm local time."
How can I take a photo of the full Moon with landmarks?
Have you ever tried to take a photo of the Moon on your phone, and it just turned out as a fuzzy, white blob? If so, you've probably wondered how photographers capture those stunning images of the Moon alongside buildings or other landmarks. Luckily, Baskill has a few easy tips to help you take some yourself.
"Thanks to the full Moon being so bright, even a mobile phone or compact camera can result in dramatic photographs of the full Moon rising in the east around the time that the Sun sets in the west," he says.
"If you really want to take a dramatic Moonrise photo, get hold of a camera with a good zoom lens, think about your favourite landmark, and wait a few hundred metres west of the landmark and wait for the Moon to rise in the east.
"To do this accurately, free planetarium software such as Stellarium will tell you exactly when and where the Moon will rise on a particular day, and online maps can help you plan where to wait with your camera."
About our expert, Dr Darren BaskillDr Baskill is an outreach officer and lecturer in the department of physics and astronomy at the University of Sussex, and an astrophotographer. He previously lectured at the Royal Observatory Greenwich, where he also initiated the annual Astronomy Photographer of the Year competition.