Today event of Blue Moon will Occur i.e. in August month of 2012 Moon will appear in its Total Phase (full Moon) for two times. Making the Second Full Moon Visible on 31st August to be referred as Blue Moon.
Generally in a Calendar year at least one Full Moon is visible in the sky every month. However sometimes rarely two full moons appear in same month. Hence in the western folklore metaphorically to describe the rarity of this occurrence of second full moon (like on 31st August) in a month is popularly referred to as Blue Moon.
Dates of Full Moons in August 2012: In August month this year 2012. First Full Moon appeared on 2nd August, 2012. Whereas Second Full Moon will appear on 31st August, 2012.
Direction – Time to watch: On 31st August 2012 one can look towards East Direction to see Moon which will Rise at 6.13 p.m. whereas technically speaking the Moon will however reach its fully illuminated Total phase at 7.28pm.
When was last time - Blue Moon Event Occurred and when is Next One?
The last time “Blue Moon” event occurred was on 31st of December Month in 2009 (2 Dec 2009 & 31Dec 2009). The next time it will occur is on 31st of July Month in 2015 (2nd July 2015 & 31st July 2015).
How Moon will appear on 31st August, 2012? Will it Appear Blue?
No, Full Moon on 31 August will not appear Blue just because it’s Second Full Moon in Single Month or it is called so. It would be like any other Full Moon which people usually observe.
Explanation Notes :
Can there be two blue moons in a single calendar year? Yes. It last happened in 1999. There were two full moons in January (2nd & 31st) and two full moons in April (1st & 30th) and no full moon in February. So both January and April had Blue Moons. The next year of double blue moons is coming up in 2018 (Jan & March).
Explanation Notes :
Brief About Various Phenomena :
Moon’s Motion around Earth: The Moon takes 27.3 days to orbit Earth, but the lunar phase cycle (from new Moon to new Moon) is 29.5 days.
The Moon spends the extra 2.2 days "catching up" because Earth travels about 45 million miles around the Sun during the time the Moon completes one orbit around Earth.
Phases - New Or No Moon – Full Moon: At the new Moon phase, the Moon is so close to the Sun in the sky that none of the side facing Earth is illuminated. In other words, the Moon is between Earth and Sun.
At first quarter, the half-lit Moon is highest in the sky at sunset, then sets about six hours later.
At full Moon, the Moon is behind Earth in space with respect to the Sun. As the Sun sets, the Moon rises with the side that faces Earth fully exposed to sunlight.
Reason for Blue Moon – Frequency: In a year twelve full moons occur approximately monthly, but in addition to those twelve full lunar cycles, each calendar year contains an excess of roughly eleven days. Which is due to difference (29.5 x 12 = 354 Days whereas our calendar consists of 365 Days) in Lunar/Solar Year. Hence these extra days accumulate, and every two or three years (on average approx 2.7154 years), there is an extra full moon. Such an extra Full moon is called a "blue moon”.