It was Christmas Eve, 1968, and the space race was in full flow. As people travelled to celebrate Christmas with their families on Earth, the crew of Apollo 8 - Jim Lovell, William Anders and Frank Borman - circled the moon in their lonely capsule, and became the first human beings to witness the rising of the Earth over the horizon of an alien world. Apollo 8 will be remembered for countless generations to come for those first images of our fragile planet seen from space, but less well remembered is the atheist controversy that the astronauts triggered with a live television broadcast that momentous Christmas Eve, forty years ago today.

Earthrise, seen from Apollo 8, December 24th 1968