7 December

On 7 December 1952, the Third Doctor and Sarah Jane Smith, then being assisted be former adversary Tommy Ramsey, turned back a Xhinn advance invasion fleet. The cost of victory was, however, high, with many ordinary Londoners losing their lives. (PROSE: Amorality Tale)

In 1972, the last Apollo moon mission, Apollo 17, launched. The mission took the photograph known as The Blue Marble, which showed the human race how small their world was in comparison to the universe. (PROSE: Time Traveller's Diary)

According to a calendar on the Snowcap base, 7 December 1986 was a Sunday. (TV: The Tenth Planet)