The eye of an angry God!

Shipwrecked in June 1503, in what is now Jamaica, Christopher Columbus and his fellows waited for rescue ships to arrive for over six months. Initially hospitable, the natives were angered as the castaways had outstayed their welcome, and so cut off their supplies, thus starving them. On 27 February 1504, Columbus threatened the natives that God will send them an angry sign. And in three days, the moon turned red! Fraught, the natives brought food for the travellers. But was it really God’s angry eye that the natives had seen?

Regiomontanus, a German mathematician, astronomer and astrologer, had prepared an almanac containing astronomical tables covering the years 1436-1506, which Columbus had carried. The almanac had predicted a total lunar eclipse on 29 February 1504, and Columbus used this knowledge to trick the natives. Good for  him that it wasn’t cloudy that night! 

But why did the moon turn red? Shouldn’t the moon disappear behind Earth’s shadow during a total eclipse (as shown in this Bollywood movie, which drew inspiration from Columbus’ adventure)?

Let us fly to the moon, in our minds, to understand why it looks red during a total eclipse! Imagine yourself as standing in one of the moon’s craters, looking up at Earth, as she passes between the you and the Sun. As Earth does this, sunlight passing through her atmosphere is refracted into the seven colours of the rainbow, the red of which can be seen from the moon, and we see a fiery red ring glowing around Earth. From Earth, we see the red light cast on the moon, which makes it appear red! This is sometimes referred to as a blood-moon.

Now, lunar eclipses are quite common; but not the one which will occur on the night of the 27th September this year. A few phenomena will coincide on that night. Not only is it a total lunar eclipse (lunar eclipses occur only during full moons), but also the moon will be closest to Earth in its orbit around Earth (called Perigee). The moon appears to be relatively larger and a lot brighter at Perigee, when it is called a supermoon. On the 27th, the supermoon will also be a blood-moon. So, we will see a rather large, bright, red moon that night, or a super blood moon! 

These are not at all common, and the last time it happened was in 1982 - before I was born! And it will only happen again in 2033! Hopefully, luck will be smiling upon us, as she was on Columbus, and it will not be a cloudy night.

*The eclipse will begin at 02:11 on 28th September, 2015 in the Netherlands.

** Most information sourced from space.com.