13th Moon of 2012

The 'Moon illusion' as the full moon sets over the VLT telescopes in Chile. Image: G. Gillet / ESO

Before the modern calendar we use today, ancient people keep track of days by observing the phases of the moon. From New Moon to Full Moon, one cycle equals to one Month hence the origin of the word. By logic if there is one moon cycle for each month, and there are 12 months in one year, then why do we now have this 13th moon for 2012?

Answer:  The moon cycle is approx 28 days not 30 days, so there will be times of the year where we will see two full moons in one month. Read more from a previous entry about Blue Moon.