What is a blue moon and is it really blue? We’re going tohave one tomorrow so we’ll be able to see for ourselves.
A blue moon is the second full moon in a calendar month.Usually months have only one full moon, but occasionallythere’s a second one. But no one knows how these got to becalled “blue.”
It may have started in 1883, an the Krakatoa volcanoexploded in Indonesia. So much ash rose into the atmospherethat the moon looked blue. This effect lasted for severalyears afterwards. People also saw lavender suns and “suchvivid red sunsets that fire engines were called out in NewYork, Poughkeepsie, and New Haven to quench the apparentconflagration,” according to volcanologist Scott Rowland.