Saturday, October 24, 2009

Light Pollution


About 4 years ago, I landed up for the first time at Inverness, in northern scotland late evening. My colleague had come to pick me up at the airport. As we drove, it was very evident that the road was pitch dark and there were no street lights at all. I asked my colleague as to why street lights were not installed. He said that they did not want street lights as it would lead to light pollution. That was the first time I experienced Light Pollution being taken up very seriously. I had only read about how lights affect astronomers. So you can imagine how the following article which appeared today in http://www.timesonline.co.uk/ resonated with me. (http://www.timesonline.co.uk/tol/news/science/space/article6887233.ece. The picture above is also from the same article from Timesonline).
Read on ! Giri

At the end of a garden path, in a home-made observatory overlooking Wee Glenamour Loch, there is an air of expectancy among a gaggle of astronomers.
Not because it’s a good night for stargazing. It’s not: the skies are leaden and the rain is falling in stair-rods. But here, on the edge of the Galloway Forest Park, locals are preparing to celebrate its recognition as a Dark-Sky Park, an award unique in Europe, that will rank this lonely corner of southwest Scotland alongside only two other areas in the world.
Next month, the International Dark-Sky Association — based in Tucson, Arizona — will convene to ratify the report of its inspectors in Britain. Final tests, which begin tonight in the shrouded hills of Glen Trool, are almost certain to confirm a first batch of readings that registered parts of the vast and lonely forest at Bortle 2 on the international darkness scale.
Bortle 2 is as dark as it gets on dry land; only in the middle of the ocean, where light pollution is entirely absent, could you experience the profound blackness of Bortle 1.
“There will be a little bit of pride. I will be able to say ‘I live in the dark-sky park’ and I’ll push it for all its worth,” says Robin Bellerby, 69, a former headmaster and chairman of the Wigtownshire Astronomical Society. “All teachers are missionaries. This can be a solitary hobby but we like to interest people to join with us and turn their heads up.”
Barring perhaps Cape Wrath, the most remote point of mainland Britain, nothing compares with Galloway for astronomers. Far from large towns and cities — Glasgow and Edinburgh are over the hills and more than two hours to the north — and with the atmosphere cleansed by frequent rain, the quality of darkness is exceptional.
You do not need rocket science to explain why the forest park is special, says Steve Owens, the UK national co-ordinator of the International Year of Astronomy and one of tonight’s three inspectors. It’s simple: high-quality darkness depends on an absence of light. Light pollution from sodium lamps in the city “is a terrible spoiler for astronomers”, he said. “On the clearest night in London you might be able to pick out only 200 stars.”
In Galloway Forest Park about 7,000 fill the sky. Weather permitting.
Sheltered by a stand of pines near the small town of Newton Stewart, Dr Bellerby and his friends feel the benefit. The observatory sits on the edge of 320 square miles of parkland in which there are only 414 “points of light”, or houses. When the Forestry Commission asked householders for their help in the dark-sky campaign, all but three agreed to douse unnecessary lights. It probably helps that, according to legend at least, astronomy is a secret passion for many locals.
A couple of years ago, sensors that count vehicles registered a surprisingly high volume of traffic heading into the forest park in the darkest hours of night. The local constabulary, alerted to possible foul play, descended on a car park by Clatteringshaws Loch. They found not drug dealers or sheep rustlers but a group of guys in cagoules and clutching Thermos flasks, their telescopes trained on the Crab Nebula.
But not tonight, as the rain clatters on the observatory roof. “Won’t see anything, I’m afraid,” Dr Bellerby says, with the cheery demeanour of a man for once looking forward to a good sleep. Last Wednesday, “a lovely night”, he had whiled away the evening totting up the man-made objects he could see above his head: two American military satellites; two pieces of Russian rocket; the International Space Station — “that’s bloody large” — and a communications contraption. But the real joys are the heavenly delights: the Milky Way, Jupiter or even the Northern Lights.
“I never saw it for a couple of years,” Dr Bellerby said. “Then a neighbour rang me. He said, ‘Get into your garden now’. And there it was, in all its glory, from west to east and following the coast north. Extraordinary.”
The International Dark-Sky Association will deliver its verdict on November 16 or 17. Until then, the world’s only dark-sky parks remain Natural Bridges, Utah, and Cherry Springs State Park, Pennsylvania.

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