- A lunar eclipse is a spectacular celestial show, during which the bright, pearly-white disc of the full Moon turns dark, and sometimes takes on the colour of dark copper, or even dried blood. A lunar eclipse occurs when the Sun, the Earth and the Moon are so aligned that for a period of time, the full Moon passes through the shadow of Earth in space (called Earth’s Umbra).
Why is it termed Blood Moon or Copper Moon?
- During a total lunar eclipse, though the Moon gets shadowed by the Earth, sunlight passing through the Earth’s atmosphere, break down in its constituent colours and the red part gets scattered by the atmosphere and falls on the Moon’s surface, thereby making it take on a reddish copper hue. For this reason since antiquity, a totally eclipsed Moon is called a “Blood Moon”. It has no other special relevance other than the fact that the colour of the Moon looks blackish-red.
Why is it called a Blue Moon?
- This full Moon occurs twice in a calendar month, the last one being on January 2. The next one, on January 31, is termed a “Blue Moon”. The Moon does not turn blue but historically the second full Moon of an English calendar month is termed as a Blue Moon. Hence the oft-quoted phrase of a rare occurrence of any event as “once in a Blue Moon”.
- The coming lunar eclipse will be more spectacular because during the eclipse, the Moon will be near its perigee (the Moon reaches its perigee on January 30 at around 15:28 hrs. IST) and hence it will look larger than an average full Moon, and is termed a Super Moon.