Ya but our ghost didn't even know about vault of glass and the guardians went in there long long ago. Venus is full of ancient vex tech so they have been around. Maybe our ghost now wasn't around when you were alive and was sent out to find you because you were bad ass back in the day. Cabal not sure if thats legit. Not comfirmed yet. Cabal could have been the first to invade and then where pushed out to mars by fallen and hive.