If you're a regular reader then I'm sure you know by now that 2009 is the International Year of Astronomy. [For the programmers: they seem to have called their superclass constructor as 2009 is the Year of Science as well.]
The IYA is marking two anniversaries this year, namely the Apollo 11 moon landings and the first observations made by Italian astronomer Galileo Galilei. These along with the ever-amusing and escalating theological bus-war that surrounds Darwin 200 got me thinking about anniversaries.
An "anniversary" is a bit of a nebulous thing. It's the correlation of a significant event with a pretty number - any multiple of ten will do nicely. Births, deaths and major events are all acceptable criteria it seems. Given the loose parametrisation it's not a surprise to find out that 2009 is full of them...
40th anniversary of the Apollo 11 moon landing.
125th anniversary of the selection of Greenwich as the Prime Meridian
150th anniversary of construction of Big Ben.
200th anniversary of the birth of Charles Darwin.
400th anniversary of Galileo Galilei's first observations with a telescope.
500th anniversary of Henry VIII's accession to the throne of England.
800th anniversary of the founding of Cambridge University.