Why does nothing have to come from anywhere? An infinite space with nothing but the odd universe occasionally popping up! Regarding the dinosaur mass extinction/ crater thing... the craters exist although no one can prove which caused the extinction. Brief quote from some website: "The impact was so enormous it changed the shape of the earth's crust -- 22 miles below the surface of the planet. The Chicxulub crater is the first location where deformation at the base of the crust has been found in a terrestrial impact crater. The scientific team concluded that the Chicxulub crater is about 125 miles in diameter, and that 12,000 cubic miles of debris was blasted out of the earth by the impact. The impact carved out a cavity about 7.5 miles below sea level. Mount Everest, in comparison, is 5.5 miles high. Prior to this research, the size and morphology of the Chicxulub crater had been in dispute, with estimates of its diameter ranging between 180 and 300 kilometers." That's a big crater...