Based on what we know so far: the Earth, Moon, Venus, and Mars will all be playable spaces in Destiny. However, I feel it is also safe to assume that in either future Destiny sequels or DLCs more planets will be unlocked. Which brings me to Mercury... For posterity, here is all the verifiable evidence I've complied towards the possible of Mercury being a playable planet: [b]The E3 Destiny Rotuna Experience: [/b]Fast forward to 4:17min: http://youtu.be/tDZe2VJqvqk [b]The Destiny Gameplay Trailer:[/b] Fast forward to 2:14mins: http://youtu.be/y2Jx5__c1lY [b]Out Here in the Wild. ViDoc #2: [/b]Fast forward to 4:13mins: http://youtu.be/Y1OjUWw43co [b]The Destiny Geomancy Symbols, ARG Alpha Lupi:[/b] http://i.imgur.com/HQeeYt8.png http://destiny.wikia.com/wiki/Alpha_Lupi