A rare "super blue blood moon" will be witnessed on the 31st of January in parts of North America, Asia, Middle East, Russia and Australia, after about 36 years.
This event is generating a wave of excitement because it combines three unusual lunar events - an extra big super moon, a blue moon, and a total lunar eclipse. It's an astronomical trifecta.
So what is it: A Blue Moon, a blood moon and a super moon? What's the difference between all these moon types? We have a quick guide below to help you distinguish moon from moon.
Before we go further, bear in mind that, in most cases, the nicknames given to different moon events do not have large astronomical significance. In most cases, the names refer to some connection between the position or phase of the moon and the Gregorian calendar.
Here are timings in Delhi, Mumbai, Bangalore, Chennai, Hyderabad, Pune, Ahmedabad & Kolkata:-
Kolkata: 5.16 PM
Delhi: 5.53 PM
Mumbai: 6.27 PM
Chennai: 6.04 PM
Hyderabad: 5.18 PM
Bangalore: 4.21 PM
Pune: 6:27 PM
Ahmedabad: 6:21 PM
What is a Super moon?
A Super moon is a full or new moon which passes the earth at its closest point. This point is known as the "perigee".
They occur when a full moon coincides with the moon's perigee, the point in its orbit at which it is closest to Earth.
According to NASA, Perigee full moons appear about 14% bigger and 30% brighter than full moons that occur near apogee in the Moon's orbit.
Since the Moon's orbit is elliptical, one side (the apogee) is about 30,000 miles (50,000 km) farther from Earth than the other (the perigee).
The event slated for January 31 is the last in a series of 3 supermoons, with the previous two being visible on December 3, 2017 and January 1, 2018.
The ‘supermoon' name was first coined by an astrologer, Richard Nolle, in 1979.
What is a Blue moon?
Blue moons are defined as the second full moon in a calendar month. Usually there is just one full moon in each month.
This event is a rarity, as it has been found to arise once every two-and-a-half years on average, says NASA.
A full moon occurs every 29.5 days. However, aside from February, our months are longer than this period, meaning that every couple of years there is a month with two full moons.
Are they blue in color?
Blue moons aren't blue in colour at all: the name is believed to be a corruption of 'belewe moon', from the ancient word for 'betrayal' as the additional moon in a season was seen to betray the traditional definition of a season as a period of three full moons.
"Most Blue Moons look pale gray and white, indistinguishable from any other moon you've ever seen," according to NASA. "Squeezing a second full moon into a calendar month doesn't change the physical properties of the moon itself, so the color remains the same."
What is a Blood moon?
A "blood moon" happens when Earth's moon is in full eclipse. While it has no special astronomical significance, the view in the sky is striking as the usually whiteish moon becomes red or ruddy-brown. While there is no direct sunlight on the moon, Earth's atmosphere refracts sunlight, creating an indirect red light on the moon.
Why is it called blood moon?
Sometimes an eclipse moon is called a "blood moon" because of this rusty color. But why does the moon turn red, and not simply darken to black when it goes into the shadow? As NASA explains, it's because the Earth's atmosphere extends beyond the planet, and sunlight passes through it, still reaching the moon.
However, the moon is not completely blocked out and the only light that we tend to see is red, because the earth's atmosphere allows the red wavelengths to pass through, while all blue light is scattered.
What is total lunar eclipse?
A lunar eclipse can occur only at full moon. A total lunar eclipse can happen only when the sun, Earth and moon are perfectly lined up - anything less than perfection creates a partial lunar eclipse or no eclipse at all.
Data from NASA shows that stargazers in India will get to experience this rare event on the evening of January 31, as the moon rises. The total lunar eclipse will start in India from 4:21 pm and last till 7:37 pm.