I've been flying over the surface of Mars in the Google Earth Flight Simulator in honour of the landing of Mars Rover, Curiosity.
Google Earth appears to use the exact centre of the planet to work out altitude, or something. It keeps the same parameters for Google Moon and Google Mars, so when you're at the surface of these other planets, it reckons you're several thousand feet lower.
driving lessons in Wallasey? learn to drive in Wirral? driving instructor in Birkenhead?