The Natural Navigator» light pollution

Moonlight Pyjama Mayhem

admin — Sat, 09 Jan 2010 06:59:05 +0000

For better or worse I seem to have a sixth sense for when conditions are great very early in the morning. I woke at 5.30am and was instantly drawn out into the neighbouring field to take in the scene and to take a picture. The snow was being lit up from the south by the waning crescent moon, the stars were out in force and Mars was peering down in red confidence from high in the west.

I stepped over the style into the field, camera in one hand, tripod in another and then it all went wrong. To avoid waking anyone I had not stumbled around for my clothes in the dark, but opted for the worryingly standard kit for this time of day: pyjamas, thick coat and wellies. My left foot slipped a bit on the style’s ice and a successful bid to save my skin and camera led to the tripod taking a big hit. It’s knackered. A fair price for escape though, not unlike the sad loss of my Land Rover Defender before Christmas. There is a saying in aviation, ‘Any landing you walk away from is a good one’. I suspect that this is not an expression that will have those with a fear of flying racing to the airport.

Starting to shiver in cold wet pyjamas, this picture was the best I could manage. The light pollution from the south coast is clearly visible, but it cannot quite drown out Virgo’s brightest star, Spica, in the top right of the picture. The lights in the bottom right are from my local village, Eartham.

Rosy Fingers or Urban Glow

admin — Fri, 23 Jan 2009 08:40:00 +0000

Everyone who starts their day outdoors welcomes dawn, but for natural navigators it is an important time that should be both enjoyed and absorbed. Sunrise is one of the best times to check our bearings, metaphorically and literally.

Something we need to look out for on land, and to a lesser extent at sea, is the light from towns. Light pollution is a perennial fiend for stargazers, but it can also throw us if we are searching for early signs of dawn, and its effects can be especially strong if there is low cloud.

The urban glow is unlikely to throw us a curveball if we have been studying the sky for a while, but it can be a problem if we emerge from darkness and take a first glimpse. The two photos above, which I took this morning, are only separated by twelve minutes and illustrate this quite well. If we are able to watch the transition from the first to the second, it is unlikely that we will mistake the rosy hue on the right of the second picture for a true sunrise, but imagine we are rubbing our eyes and our first sight of the horizon is the second picture. The temptation would be to see that colour as the sun announcing its imminent arrival. We would be mistaken: it is the light pollution from Littlehampton, a slightly less glorious ball of orange.

Squid Lights and Starry Nights

admin — Fri, 07 Nov 2008 16:26:00 +0000

I gave a lecture at the Clothworker’s Hall in the City last night. I think it went well, no rotten fruit or vegetables came my way at least. It did mean a night in a hotel and the need to fill some time in the usual Alan Partridge style. It was at the hotel that I read the cover story in this month’s National Geographic about light pollution. All stargazers are aware of the problem and I thought that this was a story that had been done pretty thoroughly, but the NG approach was fresh and made for a satisfying read.

One sentence caused me to pause and then reread. After a second reading my jaw my have dropped a touch:

‘In the south Atlantic the glow from a single fishing fleet—squid fishermen luring their prey with metal halide lamps—can be seen from space, burning brighter, in fact, than Buenos Aires or Rio de Janeiro.’