I think he was referring to the daleks trying to turn the earth into a huge spaceship by hollowing out its core and fitting it with engines in "The Dalek Invasion of Earth"
The Time Lords also moved the Earth in The Trial of a Time Lord:The Mysterious Planet.
In DW: The Trial of a Time Lord, the planet Ravolox is revealed to be Earth, relocated to another part of the universe by the Time Lords. And DW: Journey's End revealed that (with a little assist), a single TARDIS is powerful enough to move the Earth.
The Cybermen also attempted to move the Earth in The Tenth Planet.