Fig 1 Looking SSW, 2005 Sep. 02 at 21h 56m UT. A 3 minute exposure 28mm f/3.5 ISO 400 Nikon D100.

Fig 2 Looking SW, 2005 Sep. 02 at 22h 44m UT. A 50 sec. exposure 160mm f/1.8 ISO 400 Nikon D100. Shows in greater detail the region of the constellation Scutum.

Return to dark skies?

Theoretically we are entitled to enjoy darker skies at night as the effects of twilight fall off with approaching winter.

From these latitudes astronomical twilight (see archives) lasted all night between April 25 and August 19.

Every year I look forward to the onset of autumn when it might be possible to see the Milky Way for the first time in months.

Usually, from late August, with a clear sky, it should be possible to see the Milky Way close to true midnight as it stretches across the sky from NW to SW.

Certainly, when I first came to Orkney in 1970, this was the case.

Now, on Rousay, there is considerable sky glow from Kirkwall in the south, from lights at the Rousay pier in the SSW (figs 1, 2 & 5), the Egilsay jetty in the NEE (fig 3) and from Westray due north.

Add to this the effect of shipping, especially when the support tug moors off Shapinsay, where it contributes almost as much orange glow as Kirkwall itself, and you could say the would-be star gazer has problems.

The BAA's Campaign for Dark Skies has achieved a great deal practically and in making people aware of the problems of light pollution.

Fig 3 Looking E, 2005 Sep 02 at 03h 30m UT. A 2 sec. exposure 28mm f/3.5.ISO 400 Nikon D100. The old Moon with Saturn (above right) and above Saturn, Castor & Pollux.

Fig 4 Looking E, 2005 Sep 03 at 04h 32m UT A 1/60 sec. exposure 28mm f/3.5. ISO 400 Nikon D100. Cloud seeded by aircraft condensation trails.

Fig 5 Looking E at a higher elevation than in fig. 1. The bright star top right is Vega, lower middle Altair and Deneb top left immerssed in the clouds of the Milky Way. The three stars form the Summer Triangle.

But one feels Canute-like against a tide of oncoming catastrophes in which light pollution (a by-product of our civilization's profligacy) is way down the list of priorities.

Light is not the only problem.

Aircraft condensation trails are frequently responsible for seeding cloud at high altitudes. A case in point happened a few days ago when I was attempting to observe Mercy rising in the NEE.

Even in the early hours (04 UT) aircraft were busily transiting and leaving their signatures in the form of bands of "cloud" which eventually fanned out to obliterate the planet at low altitudes (Fig 4).

It is an irony that now, when astronomical equipment is available to the amateur at relatively low prices, the conditions for observing have deteriorated markedly - especially so within recent years.

JV 06/09/05