Lost Sol

One of the constant hopes of humanity is that Eve did not destroy Sol, merely transporting it. Why she did so is not entirely known, but the common theory is to give humans a meaningful distraction - if they're searching for their home, they aren't doing other, technically potent things.

Thus, when referring to the Solar System in the context of this quest, it is called 'Lost Sol'. Currently, the Missions are dedicated to finding it, scouring every inch of the Milky Way for any trace of its existence.