Sir Patrick Moore was a famous Earth astronomer.
The Doctor apparently met him at some point in the past, referring to him as "a devil" with the ladies. He was one of many experts holding a conference over the Internet when the Atraxi were threatening to boil the Earth. The Eleventh Doctor, after providing proof that he was a genius, showed the assembled experts how to create a computer virus that would alert the Atraxi to the position of Prisoner Zero. (TV: The Eleventh Hour)
- Internet Movie Database at the