Before giving the cube to Maria, Sarah Jane moves a book out of the way called UNIT: Fighting For Humankind. This is a book written by Sarah Jane about the Unified Intelligence Taskforce or UNIT which made its first appearance in Doctor Who (1963) in the 1960s.
This episode takes place in 2008 and on 13 July 1964.
Sarah Jane Smith was born in 1951. She is 5 years younger than Elisabeth Sladen who plays her, who was born in 1946.