Galaxy Quest: The search for Britain’s darkest skies

Light pollution has become a modern scourge – and few city-dwellers can identify even a single constellation. Where can we go to enjoy the celestial wonders? Simon Usborne reports from a truly heavenly corner of Britain

(PA)

At the edge of a loch in a forest in a little-visited corner of Scotland, four men in woolly hats stand slack-jawed, their eyes turned to the sky. You could imagine the scene – towering firs, shimmering water, muddy ground hard with cold – but you would struggle to see it. Because it's dark – really dark. After a few minutes of adjustment, faint shapes come into view – the jagged tops of trees and the bend of the path ahead – but there is no moon tonight. The only illumination comes from a sky so bright with stars it's as if some celestial dimmer switch has been turned up to maximum.

"There's the great square of Pegasus, as in the horse," says Mike Alexander, a local amateur astronomer. "It's lying on its back now." He reaches into his jacket pocket for a laser pointer, which throws a sharp, green beam more than a mile into the sky. "The top left star in the square is called Alpheratz – it's an Arabic name. From there, go two stars along and two stars up. Can you see a fuzzy oval patch to one side?" I can – just. "That's Andromeda," Mike says, switching off his laser. "It's a galaxy about 2.5 million light-years away."

Andromeda is well known among stargazers as the only big galaxy apart from our own, the Milky Way, that is visible with the naked eye. It's hard to fathom its distance from our planet. When we look at the sun, which always seemed pretty far away to me, we are in fact seeing the sun as it looked eight minutes and 19 seconds ago – because that's how long its light takes to reach our eyes. Light from Andromeda makes its journey to earth in 2.5 million years. By looking at this distant smudge through nothing but sky and space I am peering back to an era when, here on earth, our hominid ancestors were just learning to use tools.

But for most of us Andromeda has disappeared behind intersecting orange domes from over-lit cities, streets and offices without off switches. Light pollution has claimed countless other constellations, galaxies, nebulae and planets – even our own Milky Way – but, if you know where to look, there are pockets of sky that still burn bright. I've travelled from London to see a final frontier in our apparent war on darkness. Galloway Forest Park covers more than 300 square miles of largely uninhabited moorland, woods and mountains in the extreme south west of Scotland. Frequent rain cleans the air, improving the clarity of the sky, while the lights of the nearest city, Glasgow, are more than 70 miles away. Last November, the International Dark-Sky Association (IDA), a network of campaigners, awarded the forest special "dark sky park" status, adding it to a handful of remote wildernesses identified as some of the darkest places on the planet.

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Mike reckons we can see about 7,000 stars above the forest. At home, I would be lucky to spot more than a hundred stars through the tomato soup-like glow that passes for the night sky. Counting celestial bodies would be one way to measure darkness, but Keith Muir, who works for Forestry Commission Scotland, prefers a gadget called a Sky Quality Meter. Held up to the heavens, it converts available light into units called arc-seconds, which fall into a scale from one to 25. "In a big city you're looking at about 15," Muir explains. The first reading tonight is 21.24. A figure of 25 is pretty much impossible to achieve. "If you went out into the middle of the North Sea, where there's no light at all, on a night with no moon and high clouds to block the light of the stars themselves, you might get 24 or 24 and a bit," Muir says. "The highest average we've had in the forest is 23.8."

It was Muir who pushed to get Galloway's dark skies officially recognised. He saw an opportunity to boost tourism when something strange happened at one of park's visitor centres. "Our monitoring equipment started showing people were regularly driving up to the forest in the middle of the night, sometimes as late as three in the morning," Muir recalls. "I didn't want to investigate in case it was something we didn't want to know about." When police checked the car park they found nothing more untoward than a huddle of men wielding Thermos flasks and telescopes.

Mike, who is 52, made the stargazer's pilgrimage to Galloway after hearing about the forest's reputation for great skies on the astronomy grapevine. He hasn't left since. Stars have been his passion since childhood but remained a hobby as he worked as an engineer in Bradford. Six years ago, he quit his job and with Helen, his wife, opened a bed and breakfast with a difference. Chunky tripods and piles of Sky at Night Magazine clutter the homely sitting room at the Galloway Astronomy Centre, while the roof of the garden shed rolls back to reveal an enormous 16in diameter telescope.

Mike's natural habitat is the dark and he now devotes his time to sharing it with beginner astronomers, as well as people like me who, when they arrive, can't identify much except the moon. "We had a couple staying just before you came who said they hadn't seen the Milky Way this clear since they'd been on holiday to South Africa," he says. "We get people like that all the time. I show them faint objects they've probably read about in magazines or seen Hubble pictures of online. But here I can show them the real thing. You're not looking at a faked-up image – it's the real galaxy or planet, thousands of millions of light years away. They just stand there and can't believe what they're seeing."

Mike's phone, as well as the one in Keith Muir's forestry office in nearby Newton Stewart, has rung off the hook since people started hearing about the Dark Sky Park award. Siva Kumar has driven for eight hours from London to spend three nights under the stars. A consultant in emergency medicine at Hillingdon Hospital in Middlesex, he finds peace in the night sky. "I don't concern myself much with religion so I like the stars," says Kumar, a Hindu who grew up and studied medicine in Sri Lanka. "They provide more questions than answers and I like that."

Kumar caught the astronomy bug two years ago and has brought the 8in computer-guided telescope his wife got him for his birthday. He's come to learn from Mike and to gawp at the Milky Way. "I can't remember ever seeing it before," he says, looking up at the broad speckled stripe that bisects the sky above the loch. Kumar thinks he has seen Andromeda through his telescope but isn't sure because stars above the deck in his garden have to compete with the fiery glow of the capital and, on some nights, the glare of floodlights mounted on the huge arch of Wembley Stadium. If anything, the darkness here is a problem. "The square of Pegasus I can easily identify in London," Kumar says. "But here it took me some time to pick out because there are so many stars. But it's beautiful."

As we get a closer view of Andromeda through Mike's portable telescope, which transforms a distant smudge into an elliptical mass that hints at the far-off galaxy's spiral shape, a bright pinprick arcs across the field of view. "Did you see that?" asks Mike, whose quiet demeanour gives way to boyish excitement when he talks – as he does at length – about the night sky. "That'll be something very small – maybe a satellite or just a piece of debris. When an astronaut dropped her tool bag last year it was brighter and that was only about a foot square." Dozens of amateur astronomers tracked the errant bag as it orbited earth after Heidemarie Stefanyshyn-Piper watched it float beyond her grasp during a spacewalk last November.

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Astronomers began grumbling about light pollution almost as quickly as man and electricity conspired to dim the heavens. As it has intensified, those grumblings have become rallying cries. Dave Crawford earned his PhD in astronomy in 1958 and spent most of his career at a mountaintop observatory outside Tucson, Arizona. Now approaching 80, he remembers a time when stargazing was easy.

"When I was a kid there were a lot of dark skies," he says on the phone from Tucson. "Through all of mankind's history there was night and day, dark and light. You could go 20 miles out of town and see everything. Now for most of us it's just light and the universe is disappearing." When Tucson started developing a glow in the early 1970s, Crawford persuaded the city to cut down on bad lights – those that throw as many rays up as they do down. His mission to protect the stars gathered pace and in 1988 he and a friend founded the International Dark-Sky Association (IDA). A group of volunteer astronomers in a ramshackle office has since become a global network with a full-time staff and more than 11,000 members. Crucially, the dark skies brief has broadened to cover more than just astronomy but also to help conserve energy, protect wildlife and, as Crawford puts it, "rediscover the human rhythm".

The impact of the vanishing night on plants and animals isn't fully understood but as early as 1897, a correspondent for the Los Angeles Times in Britain reported its apparent effects. "As the electric light is finding its way for street illumination into the country parts of England, [insects] are slain by thousands at each light every warm summer evening, battering themselves against the globes until the ground beneath is strewn with them." The report goes on to say that "the fear is expressed that when England is lighted from one end to the other with electricity the songbirds will die out from the failure of their food supply."

There are still songbirds, if fewer of them, but the sound of robins and other birds tweeting at the dead of night is evidence of the confusing effects of artificial light. Street lights and other sources of illumination are also known to disrupt the lives of bats, owls, moths and even, according to one Australian study, milk production in dairy goats. In Florida, sea turtles that have evolved to head from their beach nests to the brightest lights – for millions of years the stars on the horizon over the sea – are being lured instead towards roads and houses, where hatchlings are flattened or picked off by predators.

Where dark-sky campaigners have failed to appeal to local authorities and businesses with promises of better stargazing and healthier bats, pound signs have proved more successful. Between 2002 and 2005, the energy-hungry city of Calgary in Canada swapped all its old-style streetlights for low-power alternatives. The change not only reduced light pollution but also cut the city's electricity bill by $1.7m a year and led to a significant drop in carbon emissions.

It's figures like these that energise Eddie Henry. He's a lighting engineer working for Southwark Council in South London. The borough is home to 20,000 of Britain's 7.5 million street lights. Henry has made it his mission to purge his patch of the biggest threat to darkness in our cities: low-pressure sodium lights. "We are doing everything we can to get rid of every last one," he says. Southwark, along with councils all over the country, is slowly replacing the traditional hanging glass bowls that scatter light indiscriminately with flat lenses, which produce tight cones of light. At Burgess Park, off the illuminated strip of the Old Kent Road, Henry has also installed hi-tech lamps made up of dozens of LEDs that use 40 per cent less energy than old lights. Henry says Southwark now also gives more thought to lighting. Paths in the park that run alongside pavements that are already lit are kept dark. "Fifteen years ago we put lights everywhere but now we ask the question – should we put lighting there at all?"

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But people like light. Humans no more live like diurnal animals than we do primates. To thrive in an environment that would render us effectively blind after sundown, we have engineered the world to suit our 24-hour-a-day existence. Just as we have dammed rivers, we have blocked the night with the comforting glow of artificial light. "London will never be a place for stargazing because of the other responsibilities that need to be balanced," Eddie Henry says. "Think what percentage of the GDP must be generated in the dark – how many jobs depend on the night in cinemas and theatres. And anyway, who wants to go to a dark restaurant?"

But there are more basic reasons for our need for light: we are afraid of the dark. Plunging into a rare unlit stretch of motorway elicits a strange frisson. But why, when we can see everything we need to? Even Mike and Helen admit to having been frightened during their first nights in Galloway. "It's when you can't see things you wonder what's out there," says Mike, who uses a small torch to help navigate the path to his observatory at the bottom of the garden. "Sometimes, when the bulls in the field growl at the cows next door they almost sound like tyrannosaurus rexes." Perhaps inevitably, the forest here is rumoured to be home to a big cat, sightings of which are reported in the local paper.

In our towns and cities we dread burglars and muggers, not imaginary dinosaurs and big cats. And so we throw enough light on car parks to play tennis by and keep gardens illuminated with security lamps. The cover of darkness can be dangerous. When lights along a stretch of the Regent's Canal in North London were switched off earlier this winter to help protect bats, police blamed the dark for a spate of robberies. But there is evidence to suggest bright lights are not always effective. When, in 2006, councillors in Essex announced plans for a lights-out experiment designed primarily to cut costs, residents were outraged. But last year a police report showed that the scheme had also led to a 50 per cent reduction in crime in some areas. Similar studies and experiments have come to the same conclusion – that lighting is only useful if it helps to expose a crime taking place. A super-bright halogen lamp at the back of a deserted warehouse is probably quite helpful to anyone planning a break-in.

Further evidence suggests light at night isn't necessarily good for us. Anyone who has suffered jet lag knows that the day/night cycle, also known as the circadian rhythm, doesn't like to be disturbed. Some scientists have linked extreme disruptions with serious illness. In 2007, a team of scientists working for the World Health Organisation reported evidence of connection between night shift work and cancer. A separate study by Karl Schulmeister, an Austrian physicist, suggested a high incidence of breast cancer in nurses could be caused by "the lack of melatonin, a cancer-protective agent whose production is severely diminished in people exposed to light at night".

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All that concerns Mike is his view of the skies. Back in the forest, he continues his tour of the heavens. "What star sign are you?" he asks. Taurus, I reply. He pulls out his laser pointer and directs it above the trees. "There you go. That's the triangle of the head. The eye's a huge red star called Aldebaran. It's just starting to die but it will take millions of years. Extend outwards and you come to two really long horns charging at Orion." Next to one of the bull's horns, Mike points at the Crab Nebula, the result of an explosion so bright that when it happened in 1054 the Chinese recorded seeing it in the middle of the day. It faded within weeks and today you need dark skies and a telescope to see it.

Mike's tour brings the sky to life so that it resembles more a constantly changing array of nebulae, supernovas, shifting constellations and orbiting satellites than a pretty picture. "I always think of it as a bit like a landscape," Mike says. "We have beautiful forests and coasts and it's amazing to walk here in the day when there's no wind and the trees are reflected in the water. It's beautiful. And so is the sky at night. Seeing so much so far away gives you an odd sense of perspective that you lose if you can't see it. We are insignificantly small. When you have a bad day at work and you come up here on a Friday night when the sky's clear you just start looking at things and stop worrying about the rest of it."

The stars for January 2010

The "star" of the month is the red planet Mars. Shining bloodily in the constellation Cancer, our neighbour-world – at its closest to the Earth on 29 January – is a brilliant beacon all night long. If you have binoculars, look at the planet just above the Beehive Cluster of stars at the end of January – it will be a glorious sight.

Mars has always been the planet of controversy. In 1866, an Italian astronomer, Giovanni Schiaparelli, observed that the Red Planet was criss-crossed by a network of canali – meaning "channels". But a rich Boston banker and amateur astronomer, Percival Lowell, mistranslated it as "canals".

He became obsessed with the notion that Mars was inhabited – and built an observatory in Flagstaff, Arizona, to observe the engineering prowess of the Martians. He was convinced that Mars was a dying world and its inhabitants were desperately trying to save their planet by building a network of canals.

By the turn of the 20th century, the idea of life on Mars was well-established and H G Wells couldn't resist the notion as the theme for a story. But the possibility of water – and life – on Mars is not science fiction. The current Nasa rovers on the Martian surface, Spirit and Opportunity, have both picked up evidence of sulphide chemicals in the Red Planet's soil. Many scientists see this as evidence for the remains of ancient, evaporated oceans. And this year, the US Phoenix landing probe detected frost at Mars's north pole. And life? We're not talking about little green men: more little green slime. Because primitive life – bacteria and simple organisms – may be more widespread throughout the Universe than we had realised.

Life is incredibly tenacious. Bacteria can live in nuclear reactors, down deep bore-holes, in conditions below freezing and above boiling point, and even in the vacuum of space. Compared with this, Mars looks like a holiday destination.

Life on Mars may have already been found. In 1976, the twin US Viking probes alighted on the Red Planet. They each contained a miniature laboratory – about the size of a microwave oven – that took soil samples and tested them for the tell-tale signatures of life.

One experiment turned out positive. After feeding the soil-sample a nutrient, it detected a burst of gas – much in the way babies burp after feeding. But the pleading NASA experiment detected no carbon in the soil. The NASA line was: no carbon equals no life.

Recently, we visited a team at the Scripps Institution of Oceanography near San Diego. They were working on a very similar experiment to the one NASA ran in 1976. They pointed out that the Viking equipment was Seventies' technology and things had moved on. "We estimate that Viking would have missed of the order of 30 million bacteria cells per gramme of soil," they told us.

Life on Mars? Watch this space.

What's Up

As well as the planet Mars, you can still catch giant Jupiter low in the south west, setting around 7.30 pm. The planetary parade continues later in the night, when Saturn rises in the east at about 10.30pm. And early birds have the chance to spot elusive planet Mercury during the second half of January, when it's rising in the south east around 6.30am.

The familiar shape of Orion, the great hunter, strides across the sky, facing his adversary Taurus (the bull) and followed by his two dogs (Canis Major and Canis Minor). Higher up you'll find the twin stars of Gemini, Castor and Pollux, while almost overhead rides brilliant Capella. Meaning "little nanny goat", it's the main star of Auriga: this constellation depicts a charioteer, and the reason he's carrying a goat is lost in history ...

Diary

January 7, 10.39am: Moon at Last Quarter

15, 7.11am: New Moon; annular eclipse of the sun (not visible from UK)

23, 10.53am: Moon at First Quarter

27: Mercury at greatest western elongation

29: Mars at opposition

30, 6.17am: Full Moon

Heather Couper and Nigel Henbest

For more information about stargazing and winter breaks in Scotland go to visitscotland.com/whitestars