Stargazing 2021: what to see in the night sky this year
2021 is set to be a great year for astronomy. We reveal the planets, constellations, conjunctions and other stargazing highlights over the coming 12 months.
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The stars may be enduring, but our sky is always changing thanks to the orbits of the planets and our Moon. So what can stargazers expect to see in the night sky in 2021?
There is going to be a fantastic mix of conjunctions, planetary oppositions, eclipses and perennial favourites to see over the coming 12 months, many of which can be observed with the naked eye.
There is also arguably the UK’s biggest celestial event of the year. The solar eclipse on 10 June will be seen as an annular ‘ring of fire’ from Northern Canada, but as a large partial eclipse from across Europe. It will be the biggest solar eclipse visible from the UK for six years.
More observing guides:
- How to see the planets throughout 2021
- 13 things new stargazers should know
- 12 top tips for stargazing
If you’re all set to get lost in the wonders of the night sky in 2021 but haven’t yet filled in your stargazing calendar, read on for our top tips for astronomical observing this year.
And for more stargazing tips and advice including up-to-date celestial highlights and Moon phases delivered directly to your email inbox, sign up to the BBC Sky at Night Magazine e-newsletter.
21 stargazing highlights for 2021
The Orion Nebula at its best
When December–February
Where highest around midnight
Orion’s Belt is one of the night sky’s most easily found and best-loved sights of winter, but there’s something astonishing lurking just beneath it. The Orion Nebula, also known as M42 (one of the objects in the Messier catalogue), is a diffuse cloud of gas and dust about 1,300 lightyears distant where stars are being born in the Milky Way.
One of the brightest nebulae of all and easily visible to the naked eye, M42 is hugely rewarding in binoculars and a small telescope. Look slightly to the side of it to appreciate its brightness with your more sensitive peripheral vision.
More If you fancy having a go at imaging the nebula, read our guide on how to photograph the Orion Nebula. Or find out what else is nearby in our tour of the Orion constellation.
Mars close to the Pleiades
When after dark on 3 March
Where southwestern night sky
Remember the spectacular sight of bright planet Venus within the Pleiades open cluster in April 2020? It’s happening again, this time with the Red Planet, which will be close to the Pleiades – also known as the Seven Sisters – for a few nights either side of its closest pass on 3 March.
More Find out how to see Mars in the night sky, or see if you can observe Mars’s moons.
Mercury and Jupiter in conjunction
When just before sunrise on 5 March
Where low on the southeastern horizon
Search the eastern pre-dawn sky and you’ll find tiny Mercury, now at its maximum separation from the Sun, just 17 arcminutes above gas giant Jupiter. This conjunction between the Solar System’s smallest and largest planets will occur in the constellation of Capricornus, the Sea Goat.
You’ll likely need binoculars, but be very careful using them close to sunrise. Mercury takes just 88 Earth-days to orbit the Sun, while Jupiter takes 11.87 Earth-years.
More Read our complete guide to observing the planets in 2021, or find out more upcoming conjunctions.
Moon and Mars in conjunction
When after dark on 19 March
Where southwestern night sky
Having drawn away from the Pleiades, on 19 May Mars will be visited by a 32%-lit crescent Moon. The night before, on 18 March, a 24%-lit Moon will form a loose triangle with Mars and the Pleiades.
More Read about the phases of the Moon, and how to photograph the Moon.
The Beehive Cluster at its finest
When around midnight, February to May
Where high in the southern night sky
The Beehive Cluster is an open star cluster about 520 lightyears distant in the constellation of Cancer, the Crab. It is one of the best-looking open clusters of stars and one of the nearest to the Solar System.
Also known as both Praesepe and M44, it appears as around 60 stars in a pair of binoculars, though a dozen or so stand out.
More Find out our top tips for stargazing with binoculars or read our guide to star clusters.
Crescent Moon, Jupiter and Saturn
When just before sunrise on 6 and 7 April
Where southeastern sky
With Jupiter and Saturn having emerged in the pre-dawn skies, you can watch a 31%-lit crescent Moon pass them on successive mornings if you look low to the southeastern horizon. It will pass Saturn on 6 April followed by Jupiter on 7 April, with the former taking place in darker skies.
More Find out how to observe Jupiter and Saturn and how to observe Saturn’s moons.
The Milky Way’s core
When April–September
Where southern night sky
The bright centre of our Milky Way Galaxy lies in the constellations of Sagittarius, the Archer, and Scorpius, the Scorpion, both of which never climb that high in UK skies, so it helps to know when’s best to see them.
The area emerges from the horizon in April, rising around midnight; by mid-June it rises just after sunset and by July it’s already up after dark. The further south you travel on the planet, the higher Sagittarius and Scorpius are in the night sky, and so the brighter our Galaxy’s core. Even a trip to southern Spain or the Canary Islands can make all the difference.
More Read our complete guide on how to see the Milky Way, or for more summer stargazing discover our pick of the best summer constellations.
A crescent Moon, Venus and Mercury
When just after sunset on 12 and 13 May
Where low on the northwest horizon
Are you always among the first to spot the ‘young Moon’? A badge of honour among some keen-eyed Moongazers, there’s an extra prize for anyone out hunting for a 1%-lit crescent Moon in the post-sunset sky on 12 May, in the form of the planet Venus just 1º above.
An easier sight will occur 24 hours later when a 3.5%-lit crescent Moon is visible just next to Mercury, and above Venus. You’ll need binoculars to see this.
More Read our top tips on how to observe the Moon, or find out our best features to see on the Moon.
Venus as an ‘Evening Star’
When after sunset, April–December
Where western night sky
After spending the latter months of 2020 as a ‘Morning Star’, Venus will be a fading sight in early 2021, and lost to the Sun’s glare by March. Emerging into the post-sunset western skies as an ‘Evening Star’ in April,
Venus will be blazing at mag. –3.9 by May and even brighter in June and July as it gets closer to Mars. After a dazzling summer it will sink earlier each month and gradually slim to a crescent by December as Earth and Venus get close.
More Can you spot the green flash of Venus or photograph the ring of Venus?
The best solar eclipse since 2015
When observe from 10:07 BST (09:07 UT), 10 June
Where 23º above the south-western horizon
A rare partial eclipse of the Sun will be observable from the UK, though exactly how much of the Moon covers its disc depends on where you are. In northern Scotland observers will see as much as 32% of the Sun eclipsed, in west Wales 25% and in London 20%.
It’s actually an annular solar eclipse, with viewers in northern Canada, Greenland and far-east Russia seeing a ‘ring of fire’ around the Moon for up to 3 minutes 33 seconds.
More Stuart Clark describes the thrill of seeing an eclipse.
Venus, Mars and a slim crescent Moon
When just after sunset on 11 and 12 July
Where just above the western horizon
For those with clear western horizons there’s the tempting sight on 11 July of a very bright Venus closely flanked by a dim Mars and a 3.4%-lit crescent Moon.
The following evening the Moon will be 8.4%-lit and just above the two planets. However, Venus will appear to be 200 times brighter than Mars.
More Fancy photographing this event? Read our guide on how to photograph a conjunction.
Saturn at opposition
When dusk on 2 August
Where rising in the eastern night sky
A planet is said to be at opposition when Earth is between it and the Sun. That’s what happens to Saturn, with the ‘ringed wonder’ being at its brightest and best for all of 2021. Rising at dusk in the east and setting at dawn in the west, a small telescope can be used to glimpse Saturn’s rings, and possibly its largest moon Titan.
More Read our top tips on processing your images of Saturn
The Summer Triangle at its finest
When July and August
Where overhead around midnight
One of the anchors of the summer night sky, the Summer Triangle is something that can never be unseen once you’ve discovered it. Comprising Deneb (Alpha (α) Cygni), bright Vega (Alpha (α) Lyrae) and Altair (Alpha (α) Aquilae), the Summer Triangle has the Milky Way streaming through it.
To the left of a line between Deneb and Altair is the sparkling small constellation of Delphinus, the Dolphin, while just above Altair is tiny Sagitta, the Arrow.
More Discover our pick of the best summer stars
Jupiter at opposition
When dusk on 19 August
Where rising in the eastern night sky
Every telescope owner’s favourite planet will tonight appear to be 100% illuminated as seen from Earth and be observable from dusk until dawn.
It’s a great week – and in practical terms a great month or two – to point a telescope at the ‘King of Planets’ and glimpse its browny-orange stripes. But even a pair of binoculars with 7x or 10x magnification will afford you easy views of the gas giant’s biggest moons Ganymede, Europa, Callisto and Io.
More Read our top tips on how to see Jupiter’s moons
The Andromeda Galaxy at its best
When around midnight, September and October
Where overhead
The closest large galaxy to our own Milky Way is also the most distant object you can see with unaided eyes. A spiral galaxy of a trillion stars around 2.5 million lightyears distant, you’ll need dark skies to see M31, though it’s with a pair of binoculars that you’ll get the best sight.
It’s located roughly halfway between the star Alpheratz (Alpha (α) Andromedae) at the corner of the Great Square of Pegasus, and the star Schedar (Alpha (α) Cassiopeiae) at the point of a ‘V’ in the ‘W’ shape of Cassiopeia, the Seated Queen.
More Discover find out how to see the Andromeda Galaxy and how to photograph the Andromeda Galaxy.
Neptune at opposition
When 14 September
Where rising in the eastern night sky
Though any time this season is a good time to look for Neptune, on 14 September Earth lies between it and the Sun. This ‘pale blue dot’ can be glimpsed in a pair of binoculars or a small telescope, though only in the latter will you notice any kind of colour.
It’s just below the Circlet Of Pisces, but you’re likely to need a detailed star chart or a Go-To scope because Neptune is tough to find with the naked eye.
More Find out how to photograph Neptune and moon Triton
Northern Lights season
When January–March, September–December
Where northern sky
Also known as the aurora borealis, the phenomenon of mostly green lights in the night sky is caused by charged particles from the Sun being accelerated down the field lines of the Earth’s magnetic field.
Although the best views are from around the Arctic Circle in Iceland or northern Scandinavia, it is sometimes possible to see the aurora borealis from Scotland’s far north. Often especially active around the date of September’s equinox, strong displays of the Northern Lights ought to be getting more frequent now the Sun has entered a more active part of its 11-year solar cycle.
More Find out how to see the aurora in the UK and how to photograph the aurora.
Uranus at opposition
When 5 November
Where rising in the eastern night sky
With the ‘sideways planet’ at mag. +5.7, don’t expect fireworks, but tonight the seventh planet from the Sun reaches its brightest and largest. Opposite the Sun in Earth’s sky and rising at sunset, this blue-green world that rotates on its side takes 84 years to orbit the Sun, so its position doesn’t change much from year to year.
Best viewed through a small telescope around midnight when it’s high in the southern night sky, Uranus in 2021 is on the outskirts of the constellation of Aries, the Ram, but just as close to Taurus, the Bull, and Cetus, the Whale.
More Find out how to see Uranus without a telescope and how to photograph Uranus and Neptune.
Totality on the White Continent
When 7:33 UT, 4 December
Where Antarctica
There are few affordable options for this intrepid eclipse chase. The first totality on Antarctica in the age of mass tourism will occur early in the morning when the Sun is barely above the horizon during a time of near-constant daylight, so it promises to be the darkest 1 minute 40 seconds of the entire trip for anyone on a cruise ship close to the South Orkney Islands at around 60° S.
More Read our travel guide to see the polar solar eclipse on 4 December
A parade of planets
When just after sunset on 6, 7, 8, 9 December
Where low on the western horizon
As 2021 draws to a close there will be a parade of planets right after dark. With the Sun gone from the sky, Jupiter will be shining high in the south and Venus low in the southwest, with Saturn in between.
Better still, a slim crescent Moon will make its way through the trio on successive evenings, visiting Venus on 6 December when 8%-lit, splitting Venus and Saturn on 7 December as a 16%-lit crescent, and splitting Saturn and Jupiter on 8 December while 25%-lit. Finally, on 9 December a 35%-lit Moon will be in conjunction with Jupiter.
More Find out how to find the planets in the night sky
The ‘Winter Hexagon’ at its best
When December-February
Where highest around midnight
Here’s an asterism of the brightest stars in the winter night sky taking us into early 2022. Going clockwise from the bright star Sirius (Alpha (α) Canis Majoris) closest to the horizon, is Procyon (Alpha (α) Canis Minoris), then the bright stars Castor (Alpha (α) Geminorum) and Pollux (Beta (β) Geminorum), across to Capella (Alpha (α) Aurigae), down to red star Aldebaran (Alpha (α) Tauri), then Rigel (Beta (β) Orionis) under Orion’s Belt, and back to Sirius.
More Discover the difference between asterisms and constellations, and our pick of the best winter constellations
3 of the best meteor showers to see in 2021
Beloved of patient stargazers, meteor showers demand clear, dark and moonless skies. Getting away from light pollution is imperative if you’re to see plentiful shooting stars, but the rest of it is down to luck.
In 2021 only three meteor showers will reach peak activity when the Moon is out of the way. The Lyrid meteor shower, for example, peaks around the time of a bright Moon, so viewing after moonset is a good idea.
As luck would have it, one of them is the Perseids, perhaps the best-loved and most comfortably observed of them all.
There will be almost no moonlight interference for August’s Perseids and October’s Draconids and Southern Taurids, though December’s Geminids will peak during a first quarter Moon, and both October’s Orionids, November’s Leonids and December’s Ursids peak close to a full Moon.
It is Earth’s passage through this debris that causes meteor showers (for more on this read our guide What causes a meteor shower?). Sometimes there will be a clump of debris that unexpectedly collides with Earth’s atmosphere.
For more advice, read our beginners’ guide to meteor showers.
Perseids
Peak 12-13 August
Max. meteors/hour (ZHR) 110
Moon phase New Moon on 8 August
Draconids
Peak 8-9 October
Max. meteors/hour (ZHR) 10
Moon phase New Moon on 6 October
Southern Taurids
Peak 10-11 October
Max. meteors/hour (ZHR) 5
Moon phase New Moon on 6 October
This guide originally appeared in the February 2020 issue of BBC Sky at Night Magazine.
Authors
Jamie Carter is a travel and astronomy writer and author of A Stargazing Program for Beginners: A Pocket Field Guide
