When I was at the Dublin Institute of Technology to complete my Bachelor of Arts in International Business and languages I learned an English expression about rare events : “Once in a blue moon. ”
It seems that this expression has an astronomical origin as it is the second full moon in the same calendar month, an event that occurs every two years and a half or so.
The latest blue moon took place December 31st 2009, thus ending the International Year of Astronomy in a beautiful way.
Here is my selection for this month :