Transit of Venus
6th June 2012
   John Williams relished being a member of the British Astronomical Association. His last act before leaving home for the hospice where he died was to complete a computer program. This was an implementation in Fortran to run on a PC of an existing algorithm to calculate important points in the orbits of Venus and Mars. To this author's knowledge, the programme is still used in the production of the BAA Handbook.

   In 2012, one of these important orbital points was unusual. The closest approach of Venus to the Sun was so close that the planet passed in front of it, an event known as a transit. The program, and therefore also the handbook, predicted this event for 6th June 2012, which was exactly ten years since John Williams' death.
   Transits and other solar events are fascinating to observe, but require care. Serious precautions are needed before looking towards the sun. The BAA can advise about suitable equipment. For the most recent transit, they supplied this author with a plastic-and-cardboard viewer from Thousand Oaks Optical Ltd for little over a pound. It is not worth damaging your eyesight even for an event this rare, especially when damage is easily avoided and you see better through the viewer than without it.

   If you enjoyed the event, take some trouble to find out about why a transit is important to astronomers and spare an anniversary thought for John Williams.
Image: © demarfa -