First Doctor Who Titles Revealed

We know Doctor Who is back three weeks later than usual this year on the 23rd of April, and now the first two episode titles have been revealed. The stories, forming a two-part opening to Series 6, will be called The Impossible Astronaut and Day of the Moon. Other debated names for the episodes- set in the US and featuring a return from the enigmatic River Song and the mysterious Silence as a foe-include Year of the Moon and Look Behind You!, so perhaps the 60s timeframe makes more sense now in that the focus in America began to be placed on space travel around this time. Could the aformentioned traveller of the stars have something to do with the Silence (was the blacking out of his face in the Christmas trailer important?)? There's just over a month until we find out...