Aside from the very good suggestion of allowing the player to name thier own planet, which would be very apt considering OP1 allowed such. New Earth comes to mind.
After all Earth, is just another name for Terra, which also translates to Dirt, Sand, and Mud.
Additionally, it would be entirely possible to have say a small list of planet names preset, then using an option, the game could choose the correct planets name for the proper voice recording.
This way if a player choose one of the predefined planet names, it could then go through the intro.....
1st there was Earth, then Disaster struck (Try to show a clip of the original intro showing the asteroids hitting.) and we were forced to flee or face extinction. Then there was New Terra a place of hope for our kind, until we tried to make the planet into Earth. (play some clips of battles, and parts of the intro to OP2.) Between the plague we unwittingly unleashed and the conflict between our sister colony we were forced to flee yet again or face extinction.
Now we have come here, and we have called the planet "New Earth" (or home if the player chooses his own name.) for X number of years now.
Obviously the above is just an example, but the idea is valid.
