Why does there need to be a star on a Christmas tree?

Answer 1

There doesnt, but it is symbolic of the Biblical Star of Bethlehem. On the other hand if a fragment of a comet or meteor landed in a tree, it would destroy it as happened in the Tunguska blast in l908, huge amounts of trees were flattened or the tops burned off by the compressive heat-wave. a spire or spear-like finial- like on a flag pole makes a neat top-off point, though.