This is my own particular favourite theory regarding the birth of Jesus. Comets are made of ice, and when they get close to the sun they start to melt, creating a highly dramatic tail of debris that follows them. As a result, when seen over the horizon, the comet appears to be pointing down, which might have looked to the magi like a giant arrow, as if advertising ‘Virgin Birth happening HERE’. There’s a record of a bright comet in 5 BCE by astronomers in China, which could be a candidate for the guiding star.
