Once in a Blue Moon

In Pagasa’s astronomical diary for March, Pagasa head Prisco Nilo said the blue moon - the occurrence of two full moons in one month - is due on March 1 and 30.

“On the average, [a blue moon] takes place once every two and a half years. But the second blue moon for this year which will appear this March is an exceptional case. Since the full moon occurred on January 1 and 30, 2010 and preceded by 28 days of February, the event will be repeated on March 1 and 30, 2010. The next blue moon will be on August 2 and 31, 2012," Nilo said.