The good news is that polls continue to show that between one and two-thirds of the public thinks that extraterrestrial life exists. The weird news is that a similar fraction thinks that some of it is visiting Earth. Several recent television shows have soberly addressed the possibility that alien craft are violating our air space, occasionally touching down long enough to allow their crews to conduct bizarre (and, in most states, illegal) experiments on hapless citizens. While these shows tantalize viewers by suggesting that they are finally going to get to the bottom of the so-called "UFO debate", they never...