Blue moon and Super Moon

When there are two full moons within a month, the second full moon is called a Blue Moon.

The interval between two full moons is approximately 29.53 days. The same applies for two new moons.

A lunar eclipse occurs when the moon passes directly behind the earth into its shadow.

The earth, sun and the moon are either closely or perfectly aligned, with the earth in the middle.

The earth’s shadow blocks sunlight from reflecting off the moon, thus resulting in an eclipse – partial or total. A total lunar eclipse is dramatic, as the earth’s shadow (umbra) completely covers the moon.

This can happen only when the sun, the earth and the moon are perfectly aligned. Anything less than perfection will create a partial lunar eclipse or no eclipse at all. An eclipse does not appear every full moon because the orbit of the moon (around the earth) lies in a different plane than that of the earth (around the sun).

During totality, the moon may turn red or coppery. This happens because some light from the sun passes through earth’s atmosphere and is bent towards the moon.

While other colours in the spectrum are blocked and scattered by the atmosphere, red makes it through. And it is called Blood Moon. It is not a scientific term.

The moon’s orbit around the earth is distinctly elliptical. The point when the moon is closest to the earth is called Perigee and the point when it is farthest from it is called Apogee.

When a full moon occurs at its perigee, it is called a supermoon. It is a rare event, as it has to satisfy two conditions – the moon must be closest to the earth and it should be a full moon.

At this point, the moon is observed to be 30 per cent brighter and appears 14 per cent larger. But such difference cannot be seen with the naked eye.

The moon will not be originally pink. It got its name from the pink wildflowers (Wild Ground Phlox). These flowers bloom in the spring and are native to North America.

Further, there are many other names for this moon. Such as Sprouting Grass Moon, the Egg Moon, the Paschal moon, and the Fish Moon.

It is rare to have a condition that favours the occurrence of a blue moon, a supermoon and a lunar eclipse.

For India, the three events coincide after a gap of 36 years. India had the last blue moon eclipse occurring on December 30, 1982. The interval varies for different regions. The last time the three celestial events coincided for the United States was on March 31, 1866, which is 152 years ago.