Photograph courtesy NASA, ESA and H.E. Bond (STScI)
This 2002 Hubble Space Telescope picture of the star V838 Monocerotis and surrounding dust clouds has been said to contain evidence of a phantom world—alternately called Planet X and Nibiru—that is on course to collide with Earth in 2012.
(See "2012 Prophecies Sparking Real Fears, Suicide Warnings.")
But, said NASA astrobiologist David Morrison, "there is no object out there. That's probably the most straightforward thing to say."
The origins of this theory actually predate widespread interest in 2012 and the Maya calendar. Popularized in part by a woman who claims to receive messages from extraterrestrials, the Nibiru doomsday was originally predicted for 2003.
"If there were a planet—or a brown dwarf or whatever—that was going to be in the inner solar system three years from now," Morrison said, "astronomers would have been studying it for the past decade, and it would be visible to the naked eye by now."