Complex sentence: Earth 1 and Earth 2 are now safe, with Panofsky 2 making plans to retrieve the Moon, left behind when Earth 1 was transmitted and which is no longer orbiting the insubstantial Earth 2.
Split into simpler sentences: Earth 1 and Earth 2 are now safe, with Panofsky 2 making plans to retrieve the Moon, left behind when Earth 1 was transmitted. It is no longer orbiting the insubstantial Earth 2.