The sky at night

With longer nights and crisp, clear air, winter can be a great time to discover the astronomical wonders of our night skies – as long as you wrap up warm and follow our experts’ advice.

Stars visible in the sky, above a city, at night time

Words by Matt Ray

The windswept bulk of Haytor looms ahead of us in the darkness, as I pick my way across springy grass, studded with rocks and glowing red from the light cast by our LED headtorches. At night-time, its distinctive outline partially obscures a wondrous night sky that’s scattered with burning blue and white jewels, and threaded with strands of windblown cloud.

It’s nine o’clock at night and we’re ‘star walking’ on Dartmoor. Robert Tilsley, co-founder of Dartmoor Skies (dartmoorskies.org), a local stargazing events charity, is guiding me to this granite vantage point to soak up the spectacle. Unlike neighbouring Exmoor National Park, Dartmoor has not yet achieved International Dark Sky Reserve designation but, scanning my eyes across its pitch-black, largely uninhabited interior, it’s easy to see why Robert has campaigned to make it one. 

Great Britain boasts five of the world’s 16 International Dark Sky Reserves (including the Brecon Beacons and Snowdonia in Wales, England’s newest national park the South Downs and Exmoor), as well as five International Dark Sky Parks (Bodmin Moor, Northumberland National Park and Kielder Water, Mid Wales’ Elan Valley, Galloway Forest and Tomintoul and Glenlivet in the Cairngorms), which not only benefit from low levels of light pollution, but also offer facilities that promote dark-skies education and appreciation. There are also several Dark Sky discovery sites (darkskydiscovery.org.uk) covering a range of accessible places that provide great views and have been nominated by local groups and organisations.

But serious stargazing – and night walking – needn’t be limited to these places. As long as you head to a location that offers uninterrupted sky views, is publicly accessible and away from the worst of any local light pollution – motorways, industrial estates and built-up areas – you can enjoy the wonders of the night sky.

Stars in the sky above landWinter wonders

With long nights and cold, clean air, winter is a great time to go stargazing – as long as you wrap up well (see panel, overleaf). But the first rule of star walking is to avoid a full moon, which is a massive light polluter. ‘Head out the week before the new moon,’ advises Jamie Carter, author of A Stargazing Program for Beginners: A Pocket Field Guide, who I spoke to later. ‘The moon will be rising after midnight and getting smaller every night. As soon as it gets dark, you can go stargazing through to the small hours.’

The second requirement is for clear weather. ‘Don’t be put off by not having the perfect situation,’ urges Robert as we begin our star walk on Dartmoor. It’s dry and the blustery wind is helping to break up the cloud, directly above Dartmoor, allowing us a window to the heavens. ‘You don’t have to have a perfectly clear night to see a lot in the night sky, even if there is light pollution.’

Part of the joy of star walking is that the night forces you to use your senses in unfamiliar ways. ‘You have to get used to using your peripheral vision,’ says Robert as we walk. ‘It’s more sensitive to light than the middle of your vision. So, if you are looking straight at something, then that’s your detailed view, using the cones in your eyes. Your sight around those is less detailed, but better in low light.’

Seasoned stargazers also recommend allowing 20-40 minutes for your eyes to adapt to the dark. But when you’re walking over uneven terrain in the dark, it’s important to see where you’re going to avoid injury. We light the way to Haytor with red LEDs because harsh blue light is a night-vision killer. You could easily use a rear cycle light or adapt your torch with a piece of red cellophane. ‘Smartphones are the absolute worst,’ warns Jamie. ‘So resist taking yours out of your pocket.’ 

Ironically, there are lots of free smartphone apps that overlay an augmented-reality readout on the night sky, assisting users to identify constellations using the smartphone’s internal compass and camera. There are several, such as Star Discovery, SkyView Lite and Night Sky, but Robert recommends the Star Walk app, which can help you to spot stars anywhere. 

Mapping the night sky

Winter skies in the UK are fantastic, as this is when the brightest stars are out. As we reach Haytor, Robert takes his tripod off his shoulder and attaches binoculars to it. ‘Can you see that area of bright, but indistinct, light?’ he asks. ‘That’s Andromeda, the closest major spiral galaxy to our own, 2.5 million light years away. On a clear night you can see it with the naked eye.’

My mind is suitably blown, and as I gaze up into the starfield, I struggle to process both the cosmic scale, and the information represented by the storm of flickering lights.

‘Check out all the asterisms,’ he says. Asterisms are almost informal or unofficial constellations. ‘There’s the Summer Triangle,’ he says, pointing up to the bright stars of Altair, Deneb and Vega. ‘If you can spot that, then you know where the constellations Aquila, Cygnus and Lyra are, as well as different clusters and nebula.’

One of the most recognisable asterisms is Orion’s Belt – three bright stars (Alnitak, Alnilam and Mintaka) spaced evenly in a straight line. And look just above it to find the big red supergiant star Betelgeuse, which is thought to be 700 times larger than our sun. ‘Betelgeuse is at the centre of the Winter Circle, an asterism that links up all of the major sights in the southern winter sky – including Sirius, Rigel, and Gemini,’ says Jamie. ‘They are some of the closest giant stars to us – our neighbours.’ 

Another that’s visible all year round, is Polaris, the North Star. You find it by first identifying the Plough or Big Dipper – a saucepan-shaped arrangement of stars, just beneath Polaris. Find the Plough, then find the two stars at the end of the bowl and trace a line through those two stars and follow the line four times its length to find Polaris. 

It’s easy to be amazed – yet most of the stars we can see in the night sky are not, it turns out, ‘normal’ stars. ‘The ones you can see, typically, are massive, young, blue stars and a handful of red supergiants, which burn super bright for a relatively short cosmic period of time, then explode – they’re all atypical,’ says Jamie. ‘The most typical stars in the Milky Way are red dwarfs, which are much smaller than our sun and far too dim to see [with the naked eye].’

Awe-inspiring night sights

Jamie Carter’s top five, winter stargazing highlights. 

Cassiopeia 

This M-shaped constellation goes around the North Pole, and the Andromeda galaxy is close to it. It is visible all year round from the UK, but is easier to spot during the longer winter nights.

Illustration and photo of Cassiopeia

The Pleiades, AKA Seven Sisters, M45

My favourite: it’s beautiful. It’s got seven bright stars and rises in the east in mid-October. It shines all winter, setting in February. You can see it more clearly if you look slightly to the side of it, because it’s massively bright.

Illustration and photo of the Pleiades constellation

The Orion Nebula, M42

Look to the south-east or south-west in winter to Orion’s Belt, and just below it is the Orion Nebula. It’s a star nursery, a big gas cloud, where stars are being born right now. Our sun came from an interstellar gas cloud just like it, and you can see it with the naked eye.

Illustration and photo of the Orion constellation

Sirius, The Dog Star

It’s the brightest star that we can see, although not the closest, at 8.6 light years away. Look to Orion’s belt, then go down towards the horizon and then to the east. You will come to 
a really bright star – that’s Sirius.

Illustration of Sirius constellation

Geminids Meteor Shower

This December is good for the Geminids, from midnight to 5am on the 14th. It’s the only meteor shower of the year caused by an asteroid rather than a comet, and you can get 100-120 shooting stars per hour on a good day. This year’s is almost on a new moon phase, which means no moonlight – they will be great. You can also catch the Quadrantids, which peak 3–4 January 2021, and are known for having spectacular ‘fireball’ meteors.

Illustration and photo of Geminidis meteor shower

Beyond the stars

Star constellations, asterisms and clusters aren’t the only features to look out for. Planets, distinct because they don’t flicker, also offer a thought-provoking spectacle. Staring up at the visibly Red Planet, I find myself wondering when the first human foot will step onto Mars.

‘We catch Mars up every two years or so, and the start of October 2020 was the closest we got to it,’ says Jamie. ‘We’re between the sun and Mars, so it rose opposite the sunset and set opposite the sunrise. It won’t be this bright again until 2035 but will be up for most of winter in the southern sky, straight after dark.’ Conversely, Venus – also known as the Morning Star – rises in the east, just before dawn, twice as bright as Mars. Jupiter is bright in the south-west next to Saturn – 10 times dimmer – but the two will become one on 21 December when they align and form a ‘great solstice conjunction’. While this happens every 20 years or so, the two gas giants will be just 0.06 degrees apart, the closest since 1623.

For those wishing to expand their knowledge or astrophotography skills, an organisation like Dartmoor Skies is fantastic, as are the numerous astronomy festivals and local groups across the country. And some areas offer reasonably priced equipment hire – Exmoor’s three National Park centres offer telescope hire for £25 for one night, plus refundable deposit.

As we head down from Haytor, I feel as if I have gained a cosmic perspective on things. ‘Politics, pandemics, whatever else is happening in the world, you can look up and see Venus doing its thing, with slight changes every year, which you can predict and observe,’ says Robert. ‘That feeling of absolute awe, of being a tiny thing, on a tiny planet, is the greatest.’

Awe-inspiring night sights

Jamie Carter’s top five, winter stargazing highlights.

A jacket, water bottle, sock and binocularsStar walking kit

1. Patagonia Fitz Roy Down Parka 
£319.99 eu.patagonia.com

Winter star walks will test your ability to cope in the cold, especially when you stop, so wrap up in this 800-fill certified traceable goose down, water-repellent jacket from Patagonia.

2. 360° Wide Mouth Vacuum Insulated Bottle
£25 seatosummit.co.uk

This hard-wearing, stainless steel vacuum-insulated 750ml bottle will keep your tea or coffee hot, ready to warm you on the coldest nights. It’s liner and BPA-free, too.

3. SmartWool Trekking Heavy Crew Socks
£21.99 smartwool.co.uk

A great choice for winter star walks, these heavy-weight socks feature thick cushioning.

4. Canon 10x42L IS WP Stabilised Binoculars
£1,299 canon.co.uk

Your usual pair of walking or birdwatching binocs are probably good enough for stargazing, but to hold the stars steady, you will need a tripod – or image-stabilising tech, as featured in these.

Jamie Carter is a regular contributor to the BBC’s Sky at Night magazine and author of A Stargazing Program for Beginners: A Pocket Field Guide (£34.99, Springer)