Once in a blue moon: What is blue moon? The secrets behind it

By Syed Akbar
Hyderabad, Aug 30: Do not forget to take look at the night sky on
Friday. The proverbial blue moon will occur a couple of minutes before
7.30 pm in India and if you miss this opportunity, you will have to
wait for a little more than two years to see it.

The moon however will not appear blue. It will be just like any other
full moon and charmingly beautiful. Since the lunar year is 11 days
short of the solar calendar, it so happens once in every few years
that full moon occurs twice in a month. The full moon on August 31
will qualify for the blue moon tag as a full moon had already occurred
on August 2.

“For the second time this month, the Moon is about to become full.
There was one full Moon on August 2 (in India), and now a second is
coming on August 31. According to modern folklore, whenever there are
two full Moons in a calendar month, the second one is "blue," says the
National Aeronautical and Space Administration (NASA) in a press
statement.

According to N Sri Raghunandan Kumar of Planetary Society of India, on
August 31 one can look towards east direction to see Moon, which will
rise at 6.13 pm. It will technically attain the full or total phase at
7.28 pm.

“The next time it will occur is on July 31 in 2015 (July 2, 2015 and
July 31, 2015).

Though the moon does not look blue on a blue moon day, it however does
when there is a major volcanic eruption on the earth. “A truly-blue
Moon usually requires a volcanic eruption. Back in 1883, for example,
people saw blue moons almost every night after the Indonesian volcano
Krakatoa exploded with the force of a 100-megaton nuclear bomb. Plumes
of ash rose to the very top of Earth's atmosphere, and the Moon … it
turned blue!” the NASA release said.

People also saw blue-colored Moons in 1983 after the eruption of the
El Chichon volcano in Mexico. And there are reports of blue Moons
caused by Mt. St. Helens in 1980 and Mount Pinatubo in 1991. Certain
forest fires can do the same trick.  A famous example is the giant
muskeg fire of September 1953 in Alberta, Canada.  Clouds of smoke
containing micron-sized oil droplets produced lavender suns and blue
Moons all the way from North America to England, the release added.