Hold onto your Turian, Mass Effect 3 is going to Mars.
According to Mac Walters, lead series writer for the games, Shepard will be taking a quick trip to Mars and things happen. Lots of things happen.
While it’s been confirmed we’ll be taking a trip to Earth the Palaven, the Turian home world, Mars is a new addition to the list of known locations in the game. In an interview with Game Trailers TV's Geoff Keighley, Mac Walters describes Mars as ‘integral’ to the story line, with Shepard running into old squad-mate, Liara.
Liara is apparently on the planet looking for some clues left by the Protheans, but the Illusive man and Cerberus catch on and proceed to announce their arrival by trying to crash a shuttle into you.
The neat Mars stuff can be seen at about 5:58 into the video, while there’s some nifty multi-player stuff around 14:50, too.