Introduction
The night of 31st January 2018 was special as it was a Total Lunar Eclipse and it was also a Supermoon, Blue Moon and Blood Moon !
Of the four, the first two have a physical basis i.e. the moon transiting the Earth's shadow and it being at the perigee (closest to the Earth) of its orbit. The third is an artefact of the Gregorian Calendar being used by most of the world and the fourth would seem redundant as the moon would appear reddish in all total eclipses, due to Rayleigh scattering, I presume :)
