Terra is the secret goddess of the earth. She cannot be contacted, prayed to or otherwise interacted with by the player at all. Her alignment is identical to Silva at N+ (neutral leaning towards lawful).
Since most things in IVAN require an attached god, Terra serves as a placeholder for anything considered truly neutral.
Things aligned with Terra:
The lterra file in IVAN's source code is responsible for generating the world and tiles you play the game on, as well as your interactions with the environment or objects within the environment.
Terra is actually defined in the source code and script as being the same god as Silva. As such, anything labeled TERRA in the script files is actually attached to Silva.
Unlike other gods, Terra does not have any rooms (e.g. shrines) that are specifically assigned to her.