The Space Age is the 15th and last epoch and is only available in The Art of Conquest expansion. Any civilization that has reached this epoch can create spaceships and discover new planets to expand their civilization. However, be weary of other players in this epoch as they too, are at max power. Very useful but also highly dangerous when used against you is the Teleporter, a new building that can be constructed in this epoch.
For the Space Age there are also a few new maps being only Planets. "Planets - Small" and "Planets - Large" per se, are just like "Islands - Small" and "Islands - Large", only with space instead of water!