Space

10 Astronomical Secrets of the British Night Sky

Gary Fildes, founder and director of the Kielder Observatory in Northumberland, reveals the magical nocturnal sights any amateur stargazer can enjoy in the skies above BritainFriday, November 2, 2018

By Mark Bailey
Stargazing at Snowdonia International Dark Sky Reserve, Wales.

1. You can see thousands of stars with the naked eye

“The best places to stargaze are Dark Sky sites,” notes Fildes. These locations, away from the glow of cities and towns, offer the purest conditions. Britain has International Dark Sky Reserves in Exmoor, the South Downs, the Brecon Beacons and Snowdonia and Dark Sky Parks in Northumberland, the Elan Valley and Cornwall. “The Northumberland location, where the Kielder Observatory sits, is the largest expanse of protected dark skies in Europe and the only one with an observatory. The Peak District, Lake District and Exmoor National Park are also great but you can find your nearest location on the Dark Sky Discovery website.”

The aurora lights are a northern hemisphere phenomenon, and visible across many regions of the UK.

2. The Northern Lights perform here, too

“Most people believe you have to wander off into the Arctic Circle to see the Northern Lights but you can see them from the UK,” explains Fildes. This glorious curtain of dancing lights – caused by electrically charged particles from the Sun entering the Earth’s atmosphere – is visible everywhere from the Isle of Lewis to Pembrokeshire. “What you need is a really good northern horizon and, more importantly, dark skies with no moon, so the further north you go, the better. And always check the solar weather on the Space Weather website: if the sun is active, you get more particles hitting the Earth’s atmosphere and more active Northern Lights.”

The cosmic 'phantom' in this image lies along the northern Milky Way, in the Cepheus constellation, and is nearly 1,400 light-years away.

3. Go in search of the Milky Way

The Milky Way, the galaxy which contains our Solar System, is “the jewel in the crown of astronomy,” says Fildes. “You need dark skies but the best time to see it here is during the spring, summer and autumn. It is a wonderful sight - a collection of millions of stars. They are so far away our eyes cannot resolve them as individual points of light but their light combines to create this milky glow in the sky. You won’t mistake the beautiful band of brightness.”

The diagonal beam of light, visible behind Venus, is zodiacal light, which is sunlight scattered by dust.

4. Watch out for zodiacal light

Zodiacal light is a faint triangular glow caused when sunlight is scattered by interplanetary dust. “It is especially good in the autumn and spring,” explains Fildes. “Some of the dust and gas particles are from comet impacts, and some are leftovers from the formation of the solar system. You will see a triangle of light coming up from the horizon, pointing up towards the zodiac.” That is why it is also known as a ‘false dawn’ or ‘false dusk.’ “I have seen it in the Atacama Desert in Chile but I have also seen it in Northumberland,” insists Fildes.  

Gary Fildes, founder and director of the Kielder Observatory in Northumberland.

5. Remember, even dark skies aren’t that dark

“When people say they can’t see their hand in front of their face on a dark night, it’s a load of rubbish,” says Fildes. “Even our dark skies are not that dark. The sky is alive with so many sources of light that even on seemingly dark nights there are millions of stars pinging around.”

It took a five-minute exposure to capture this image of the nebula, IC-434, in the Orion constellation.

6. City-dwellers can spot Orion, too

“Dark skies always offer the best conditions but it’s amazing what you can see in cities,” reveals Fildes. “I remember being in the centre of London five to six years ago, near Covent Garden, and I could see the constellation of Orion with its bright belt stars.” Excluding the sun, the Orion constellation contains two of the 10 other brightest stars in the night sky: the blue supergiant Rigel and the red supergiant Betelgeuse.

The annual Perseid meteor shower delivers a spectacular dark night show.

7. Soak up some meteor showers

“You can also see meteor showers from inner cities,” explains Fildes. These spectacular shows are caused by streams of cosmic debris entering the Earth's atmosphere at speed. “The two big meteor showers of the year – Perseids and Geminids – are especially visible. Perseids peaks around August 11-13 and Geminids from December 13–15. You can sit in your back garden and count the meteors. The majority happen just before sunrise so it is worth getting up for, but you can see 60-80 an hour at the darkest sites.”

This spectacular starlit night was at Loch Cluanie in the Highlands of Scotland.

8. Become a planet-hunter

“If you have a small telescope, all the planets are visible to you, no matter where you are,” insists Fildes. “That is especially true of the bright planets such as Venus, Mars, Jupiter and Saturn. Through a telescope these planets are so bright the details are really fine and the resolution is excellent.”

The Andromeda Galaxy, seen from the New Mexico Skies observatory.

9. Explore the Andromeda Galaxy

“People don’t realise that every point of light you ever see in the night sky is a star that lives inside our own Milky Way galaxy,” explains Fildes. “You can’t see any stars beyond that with the naked eye – except, that is, our closest neighbour, the Andromeda Galaxy.” This appears as a beautiful spiral of light. “It is 2.5 million light years from us and in a dark sky it appears as this beautiful fuzzy patch of light, with over 1 trillion stars in the galaxy.”

10. Dark nights reveal the secrets of the Big Bang

Even an apparently empty night sky is more interesting than you think. “The darkness reveals a lot about the creation of the universe,” notes Fildes. “The modern Big Bang theory says that it was created around 13.5 billion years ago. If our universe was infinitely old, it would be filled with an infinite amount of stars that would have been shining light in all directions for an infinite amount of time. So the sky could never be dark and would burn as bright as the sun.” But because the universe is of a finite age, the light from distant stars becomes dimmed as they recede and the universe expands, causing darkness. This is a theory known as Olber’s Paradox. “The fact that the night sky is dark is a direct indication that our universe had a beginning,” concludes Fildes. “So even a dark sky gives us an extraordinary insight into the evolution of our universe.

An Astronomer’s Tale by Gary Fildes is out now.