Could natural disasters really be the work of extraterrestrial forces? in 2011, after a 30-foot tsunami ravaged Tohoku, Japan, the local media reported more than 1, 000 UFO sightings over the inundated shoreline. Did otherworldly beings that descended from the sky have anything to do with the abrupt disappearance of the Mayans?. Does the Mayan Long Count Calendar, in which the world ends on December 21, 2012, give credence to the Doomsday Prophecies? Are Grey Aliens real? Many have claimed to have been visited and even abducted by them. Is NASA sharing all that it knows about the universe? Or are they protecting US from the truth? ANCIENT ALIENS SEASON FOUR continues to examine 25 thousand years of the most credible alien evidence here on earth.