They're evidence of extraterrestrial visitation, time travelers or lost civilizations like Atlantis - or perhaps they're here to show us that some ancient peoples were far more advanced than we think.

Space shuttle Atlantis ended its 2-day journey at 11:51 am Wednesday as the shuttle arrived at the International Space Station. The 2 ships were sailing above the coast of Australia when they met.

At 11:29 a.m. Eastern Daylight Time on July 8, 2011, the space Shuttle Atlantis lit its rockets and roared into space.