In the run-up to our Halloween session, it seemed like the odds were stacked against us. There was no consensus in the weather forecasts, with the majority predicting disruptive cloud cover. The Blackheath Fair was much closer than normal, having moved fields to the Lewisham side of Shooters Hill Road. And preparation work for the Blackheath Fireworks the following weekend meant that ground protection mats, laid for the tractors bringing in fencing, were all over our observin

At around 9pm on Saturday, I was beginning to think the clouds might have brought our evening to an end. Two astronomy explainers from the Royal Observatory had just arrived, and I was concerned that they would leave without seeing anything. I just about managed to show them Almach through a gap, with its golden-yellow and blue components. Then, almost out of nowhere, the sky cleared overhead and we got a wonderful view of Saturn, now higher in the south-east. Their reaction