The Dark Sky: Part 2

by Duncan Lunan

After the first US weather TIROS satellites in the early 1960s, the seven Nimbus satellites dominated weather forecasting from the mid-60s to late 1970s, until followed by the World Weather Watch satellites in geosynchronous orbit. 

Nimbus weather satellites

The Nimbus satellites were in ‘Sun-synchronous’ orbits, 500 to 1000 miles up, passing over the same regions of the Earth’s surface at the same times each day.  Gravitationally stabilised, perpendicular to the Earth below, they scanned continuously in strips which could be built up into vertical maps, only slightly distorted in longitude as the Earth rotated below them.  And although the main purpose was to photograph and monitor cloud patterns on the sunlit side of the planet, they could also photograph city lights on the night side – and the results were dramatic.  Even the early photographs of the British Isles, for instance, showed how much of the country was already blanketed by light pollution, hiding the beauty of the night sky from the majority of the population and pretty well everybody in the towns.  As global mosaics were produced, it became apparent that over most of the ‘civilised’ world, the view of the night sky which the human race had enjoyed for all its history to date was simply gone.

Nimbus UK strip

One of the most startling revelations was that when seen from space, the fourth brightest thing on the night side of the planet was the Central Belt of Scotland.  The brightest was the Aurora Borealis, second brightest was the Japanese Pacific fishing fleet, the third brightest things were natural brush fires in Africa, but the next brightest and the second brightest man-made one was the Central Belt.  That might seem fantastic, given the local brightness of New York, say, or Los Angeles.  In my 1986 article on ‘Astronomy in New York’, I described how the Empire State Building cast an inverted black pyramid of shadow up into the sky on cloudy nights.  But relative to the Earth’s surface, New York and Los Angeles are just spots of light surrounded by relative dimness, whereas the Central Belt was a solid bar of light from Greenock to Grangemouth, breaking up into individual towns only at the highest resolution.  And every watt of that was wasted energy;  there are no muggers, murderers or motorists 1000 miles up, and every ground-based light which you can see from that height is wasting energy in a big way.

Global light Pollution

There was confirmation of that in the Glasgow Parks Astronomy Project in 1979, when one of my staff was a professional site-tester temporarily made redundant from the Royal Observatory Edinburgh.  Glasgow University’s historic observatory on University Gardens  (which I had been privileged to use once as a student)  had been demolished to make way for the new Queen Margaret Union, and the University had built a new one on Acre Road, only for it immediately to be compromised when the city built an incinerator due south of it.  The Astronomy Department had no funding to search for a new site, but I was able to get Donald seconded from my team to theirs.  After completing a survey for them, he reported that there was nowhere in the Central Belt with a dark enough sky for scientific purposes, and the out-station had to be set up in Argyllshire. 

On a less professional basis, organisations like the International Dark Sky Association were beginning to organise and take stock of the situation.  In events like their Dark Sky Week they would ask members of the public to conduct their own sky surveys, for instance by counting how many stars they could see within a fixed area like the constellation Orion or the Great Square of Pegasus.  Year by year, it became apparent that only a small percentage of the population had access to a truly dark sky, and the problem was continually worsening.

International Dark Sky Week banner

I believe that I played a small part in the events which followed.  I was friends with a senior lighting engineer who had responsibility for the lights on the motorway cutting through Glasgow, and we often debated the issue.  My major piece of ammunition was that in Arizona, the city of Tucson had adopted dark-sky compatible lighting for the benefit of the Kitt Peak National Observatory, one of the USA’s major scientific sites, and had found they could reduce the municipal energy bill by 35%, without reducing the level of illumination at ground level.  My friend’s invariable reply was that nevertheless, the cost of changing the system would be too great  (I’ve heard similar arguments about chemical pollution elsewhere).  But when the time came for the lights to be renewed, in the normal operational cycle, nevertheless it was done.  Suddenly, from my 9th-floor flat in Anderston overlooking the Kingston Bridge, seen from above the M8 became a dark lane through the city.  The effect was particularly dramatic from below the underpass where the approach lanes to the bridge pass over Anderston Station – suddenly there was dark sky above.  And within a year, it was announced that the whole of Britain’s motorway network would be doing the same, on a replacement basis – purely to save energy, of course.

More dramatic events followed.  The British Astronomical Association formed the Commission for Dark Skies in 1989, becoming the largest group of its kind in the International Dark Sky Association.  The Campaign for the Preservation of Rural England took up the cause, leading to a 2003 report by the Parliamentary Science and Technology Select Committee, followed by the inclusion of ‘light intrusion’ in the Clean Neighbourhoods and Environment Act of 2005, followed in turn by the 2009 report of the Royal Commission on Environmental Pollution, on Artificial Lighting and the Environment.  Since then, official dark sky protection areas have been declared in County Kerry, southern Ireland, in parts of the Highlands, in the Galloway and Kielder Forests, and in the West Country.  Last year’s destruction by fire of the Scottish Dark Sky Observatory above Loch Doon in Ayrshire is a major setback, but there are hopes that it will rise again.

Scottish Dark Sky Observatory

One of the backers of the 2003 report was Tom Harris, MP for Cathcart, and as a result when it was published in London there was a simultaneous event at the Glasgow Science Centre on October 6th that year, where it was announced that the whole of Greater Glasgow would be going over to dark-sky compatible municipal lighting over the next 20 years.  I was there as a Curator of Airdrie Public Observatory, and during the event Tom Harris came up to me, shook my hand and said, with this emphasis, “I’m very glad that you’re here, Duncan”.  There was no more said, but it did encourage me to think I had some part in what was taking place.

Of course, the announcements weren’t universally welcomed.  One of the less helpful contributions came from Esther Rantzen, who tried to start a children’s campaign against Dark Skies.  “Don’t let the nasty astronomers turn off the street lights, because we’re afraid of the dark.”  It completely missed the point and got nowhere, as far as I know, because the point is not to switch off the lights, just design them to shine efficiently where they’re needed.  As children’s environmental campaigns go, it has to be ranked with Enid Blyton’s one to end the 1950s cull of grey squirrels and allow them to spread north unimpeded.

Although the Glasgow action had a 20-year timescale, the results were immediate.  Within a year, crossing Blythswood Square on the way to Anderston one winter night, I realised that I could see the Orion Nebula in his Sword, with averted vision. 12 months earlier, in that location I would have been lucky to see the Belt.  From my flat, the view of the South Side and east over the city centre had gone dark.  The difference can clearly be seen in the photographs of moonrise at furthest north, in 2006, and Rigel rising in 2009, taken by Mark Runnacles at the Sighthill stone circle in Glasgow.  In the first the sky is orange, in the second it’s blue – compare the sky over Stirling Observatory, in Dr. Alan Cayless’s photo of Comet Pan-STARRS 3 in 2013. 

Alan-Cayless. Comet PanSTARRS-, Stirling Observatory, Mar 15 2013

About the same time it was announced that North Lanarkshire would be following suit with dark-sky compatible lighting, and there was scope for that.  The first Airdrie Public Observatory was established on the roof of the Public Library in 1895.  When the ‘New’ Library financed by Carnegie was opened in 1925, Bailie James S. Lewis supervised the installation of a Victorian refracting telescope, on a mount made by Thomas Cooke of York, and arranged for surrounding street lights to be capped for its benefit.  By the time I became Acting Curator in 1978 and later a full Curator, off and on to 2008, that provision was long gone.  In 1986 Monklands District Council suddenly decided that I must show Halley’s Comet to the public before it disappeared, but it was extremely difficult because it was low over the Town Hall and of course the floodlights couldn’t be turned off.

Worse was to come, however, when it was announced that four building around the Observatory were to be floodlit.  The oldest public observatory in Scotland, the Coats Observatory in Paisley, was unusable at the time because it had been floodlit for its hundredth anniversary, with no off-switches installed.  My urging that the Airdrie floodlights should have them was initially successful, but then the County accountants intervened and insisted that £100 should be saved by not installing them, though it would cost far more to do it later if ever it was to be.  At that point there was a bare patch of ground opposite the Observatory being used as a car park, and when the Senior Curator, the late Prof. Oscar Schwiglhofer, was asked what was to be built there, he replied, “I don’t know, probably a lighthouse!”  Our new King took a hand when the Observatory was threatened with closure altogether in 2002, writing in his capacity as the Duke of Rothesay  (the ‘Scottish title’ which he mentioned in his Address to the Nation?)

SDSO destroyed 2021 (Ayrshire Post)

Meanwhile in the 1980s there had been a scare about the impending return of Comet Swift-Tuttle, the Great Comet of 1862.  It’s the parent comet of the Perseid meteors and its orbital period had been calculated as 120 years, creating a serious chance of a collision with Earth – some estimates put the chance as high as one in 40.  David Langford, the Science Editor of the short-lived Extro magazine, commissioned an article from me for Issue 4 of what proved to be a 3-issue run.  After a long and complicated history, the article was eventually published in Analog in 1994, and was incorporated into my book Incoming Asteroid!  (Springer, 2013).  The comet didn’t come back till 1992, when it passed far from Earth;  but its nucleus turned out to be 26 km in diameter, so in future encounters there’s a serious chance of a much worse impact than the dinosaur-killer 65 million years ago.

For all these reasons I was very keen to see it on its brief 1992 pass.  An attempt at the Three Sisters observatory pillars in Largs was a failure, because they’re on a hilltop, now in a housing estate and surrounded by lights.  But a full evening spent on it at Airdrie Observatory was completely frustrating because the comet was right next to the newly floodlit church spire to the north, quite impossible to see. 

Comet-Swift-Tuttle_NASA 1992

Afterwards, waiting for my train under the blinding overhead lights of Airdrie Station, the muse came upon me and I composed the ‘Campaign Song for Dark Skies’ below.  It goes to the tune of Where Is the Glasgow that I Used to Know?, by Adam McNaughtan  (imitation is the sincerest form of flattery), and was published in International Spacereport, June 1994, reprinted in the Scottish Astronomers Group Magazine, July 2002.    


By Duncan Lunan

Tune: Where Is the Glasgow? by Adam McNaughtan; published in The Scottish Folksinger, edited by Norman Buchan and Peter Hall, Collins, 1973.  Last line of each verse half-spoken.

1. Oh where is the night sky that I used to know,
    Which now you can't see for a bright orange glow,
    Where you knew every star down from 1st mag. to 3rd.,
    And not to see 4th was considered absurd -

Now do you know that Vega's supposed to be blue?

2.  And where's the star finder that all of us knew,
     From Philips, all cardboard, in black, white and blue?
     Now you buy them in plastic, they're even more grand,
     But you can't see the stars that you hold in your hand.

Can you find the Beehive even when there's no Moon?

3.  And where is the dealer that I knew so well,  [Charles Frank Ltd., Glasgow]
     Down on the Saltmarket where they used to sell
     A bag of broken lenses, six-inch mirror kits,
     And build-your-first-scope out of second-hand bits.

Are there any firms left that give service like that?

4.  Is Norton's Star Atlas still used as a guide
     For the Messier objects they've plotted inside?
     Though it says, "For a six-inch, this cluster's a test",
     If you can't see the guide stars you can't find the rest.

Since the church spire's been floodlit, the heavens are bare.

5.  And where's the old gaffer who lived down the street,
     With a brass-tubed three-inch on its unstable feet?
     On its pillar-and-claw stand, it shook like a wand,
     But he'd still show you stars at the back o' beyond.

Now is he mugged by yobs if he ventures outdoors?

6.  How can we give kids the Universe back?
     Put caps on the street-lights, the sky will turn black.
     The stars are still up there, if only they knew -
     On the energy savings, 'Dark Skies' can win through.

If you turn off the floodlights, the stars are still there.


Verse 1:  Vega is the brightest star in the constellation Lyra and the Summer Triangle – see ‘The Autumn Stars’, Orkney News, 28th August 2022.  Vega is a blue giant star 25 light-years away and when not washed out by lights, its colour is distinctive, to the naked eye and still more with binoculars.

Verse 2:  I mentioned planisphere star finders in Beginners Part 3, ‘Co-ordinate Systems’, 4th April 2021.  They’re devices with two superimposed circles and a mask let into the upper one.  You set the date and time you want by matching them up at the edges, and the area within the mask then gives you the stars which are in the sky at that time.  The first one I used was with the Marr College school telescope in 1957 – in those days they were made of cardboard, usually by Phillips.  I bought my first one at the London Planetarium in 1959 and it’s a collector’s item because the upper disc is in plastic – nowadays both are.  ‘The Beehive’, aka Praesepe, ‘The Manger’, is an Open Cluster of newly formed stars  (600-700 million years ago)  in the constellation Cancer.  Some old maps represent it as the tuft on the tail of Leo, the Lion.

Verse 3:  ‘the dealer’ was Charles Frank & Sons Limited, Glasgow, who had a shop on the Saltmarket, a showroom on Ingram Street, a workshop on Cochrane Street and a display window at Central Station.  The late Bill Braithwaite and John Braithwaite of the Glasgow Parks Astronomy Project both worked there, and John subsequently became the last telescope maker in Scotland  (Dalserf Optics)  until his death in 2012.  Stan Pierce and Jim Quigg were other Frank’s employees who had optics shops in Glasgow after Frank’s was bought out and closed by asset-strippers in the late 1970s.  When I sang the song at the Star Folk Club, in front of Adam McNaughtan among others, a member of the audience came up and thanked me profusely for mentioning the firm, where his father had also worked.

Verse 4:  Norton’s Star Atlas, produced by Gall & Inglis, was a set text for the first year astronomy class at Glasgow University, under the late Prof. Archie Roy in the 1960s, and a ‘Bible’ for amateur astronomers until much later, with the maps in successive editions corrected for the ‘new’ galactic coordinates from radioastronomy, and the changes in celestial ones due to the Precession of the Equinoxes.  Later versions were edited by my friend Ian Ridpath, and the most recent was the 20th edition in 2003.

Verse 5:  The pillar-and-claw stand was a notoriously unstable telescope mount, described by Sir Patrick Moore as ‘about as steady as a blancmange’.  The Marr College school telescope had one, because it was a Victorian replica of an 18th century telescope by James Short;  I managed to stabilise it by wedging its feet around the top of an upturned orange-box. Verse 6:  Current commentators are remarking on the lack of conservation measures in the new Prime Minister’s energy policy.  ‘…it made the situation worse by making no attempt whatsoever to encourage conservation – absolutely critical to avoid supply shortfalls that could result in blackouts. In a 1,267-word speech, Truss didn’t mention the words “demand,” “consumption” or “savings” once.’  (Javier Blas, ‘Britain goes the wrong way on energy bailout’, Global Warming Policy Foundation, 9th September 2022.)  A 35% cut in municipal energy bills, like Tucson’s, would be a very good start.  Replacing inefficient streetlights would be a lot cheaper than insulating millions of homes or converting them to air-pump heating, for which many northern homes are unsuited, as Orkney News has pointed out.  I hope there will be a lot more to say on this.

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