I didn’t know until very recently about the kooky theories surrounding Planet X — not in 1930, I mean, but right now, today. While I won’t link to any of the real loonies directly, a quick read of the Wikipedia entry on the Niburu collision should give you a sense of what kinds of lunacy people are capable of committing to. (In sum, the belief involves a NASA conspiracy to cover up the existence of a giant 10th planet on a collision course with Earth.) The most strenuous advocates of this belief appear to be either deeply delusional — I mean, mentally ill — or outright charlatans. Charlatanism is entertaining, but untreated mental illness ain’t.
Happily, the forces of good are hard at work. The excellent Phil Plait, of Bad Astronomy fame, is on the case against the Planet X conspiracists. Of course, demonstrating logical fallacies, misconceptions, misunderstandings, and the like to a group of conspiracy theorists is sort of like describing soccer to your cats: they might appear to be listening, but their behavior never seems to change.
But someone’s got to stand up to the kooks. One more hurrah for the scientists among us! And as Phil Plait says: