At the May 3rd monthly meeting of the CDAA, David Peck gave a presentation entitled 'The History of Pluto'. The story of Pluto's discovery began with the realisation that perturbations in the planet Neptune's orbit implied the presence of an undetected 'Planet X'. Percival Lowell using the more acurately known orbital path of the planet Uranus, calculated a mass and orbital period for 'Planet X' but got it completely wrong. Pluto was eventually discovered in 1930 by Clyde Tombaugh. He had painstakingly studied numerous photographs of the night sky taken days apart, using a 'Blink Comparitor'. This allowed two photographs to be switched in the field of view rapidly. With background stars remaining stationary, moving objects such as planets would appear to flick between two positons, making their presence obvious. An 11 year old Venetia Phair (née Burney), living in Oxford, England, was the first person to suggest the name Pluto for the planet.
The next meeting will be held as usual at the 'Friends Meeting House' in Granville Road, Clacton on June 7th 2007. We have a special guest speaker - Peter Meadows - talking about 'Solar Observing'.