British Astronomical Association
Picture Of The Week

30-Jan-2006

Saturn at Opposition

By David Arditti

David writes:
"I was amazed when I looked at Saturn last night, about 02:00 when the clouds cleared, within 4 hours of opposition. The rings had a brilliant, bluish-white luminous quality.

I have made a colour composite image, but I am not very happy with the colours. However, the individual channels show clearly the reason for the remarkable appearance. The red and green images are more or less normal, but in the blue, whereas normally the rings and globe are of similar intensity, and much dimmer than in the R and G, the rings now shine out almost as bright as in the R, leaving the globe dull by comparison. The almost fluorescent quality this gave them, visually, cannot be well-represented in a colour image.

We were lucky in Europe to have opposition occurring close to midnight our time, which meant almost the most favourable opportunity possible for observing the opposition Seeliger effect."