The phenomenon of UFO doesn't say anything about the presence of intelligence in space. It just shows how rare it is here on the earth.
Arthur C. ClarkeThe Earth would only have to move a few million kilometers sunward-or starward-for the delicate balance of climate to be destroyed. The Antarctic icecap would melt and flood all low-lying land; or the oceans would freeze and the whole world would be locked in eternal winter. Just a nudge in either direction would be enough.
Arthur C. Clarke