Blue Moon

This is a trip: "There was a time, not long ago, when people saw blue moons almost every night. Full moons, half moons, crescent moons - they were all blue, except some nights when they were green. The time was 1883, the year an Indonesian volcano named Krakatoa exploded. Scientists liken the blast to a 100-megaton nuclear bomb. Fully 600 km away, people heard the noise as loud as a cannon shot. Plumes of ash rose to the very top of Earth's atmosphere. And the moon turned blue. Krakatoa's ash is the reason. Some of the ash-clouds were filled with particles about 1 micron (one millionth of a meter) wide - the right size to strongly scatter red light, while allowing other colors to pass. White moonbeams shining through the clouds emerged blue, and sometimes green."