Rosy Fingers or Urban Glow

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

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.'