 What is the aliens' goal on the surface of Earth?
Earth was so far away that it wasn't visible. But this vast distance did not mean that isolation could endure forever. The history of the planet was tabulated as facts became available. A meteor shower could pass over and their clumsy instruments could interpret it as an all-out enemy attack." "And how long can Earth last? They went much closer to Earth, not intending to commit themselves. For a day they circled the planet, avoiding radar detection, which for them was not difficult, testing, and sampling. "What's worse is that I now find they also have missiles, range one thousand miles and upward. The southern plains were green, coursed with rivers; the oceans were blue; and much of the northern hemisphere was glistening white.
 They want to keep the humans from fighting and destroying themselves
 They want to delay any wars until they can come back to help with backup  They want to defuse the bombs  They want to keep the humans from fighting and destroying themselves  They want to officially connect the alien culture and the humans' culture