 Why is it significant that the aliens only differ from humans in one physical characteristic?
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." Except for the one thing they lack, and that's quite odd, they seem exactly like us. 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.
 The aliens happened to look like certain beings from stories of Earth's history.
 The aliens happened to look like certain beings from stories of Earth's history.  The fact that humans are shorter makes the aliens more imposing.  It proves that the aliens and humans are actually distant relatives.  It means the aliens will not be trusted when they land on earth.