A New theory from Harvard on Dinosaurs were extinguished on Earth [npr.org]

~ According to this new theory, the devastation came from a sort of long-distance comet that came from the edge of the solar system in an area known as the Oort cloud.

~ The gravity from Jupiter pulled the comet into the solar system. Jupiter acts as a kind of pinball machine.

~ Jupiter's gravity shot this incoming comet into an orbit that brought it very close to the sun, whose tidal forces caused the comet to break apart. Some of the comet's fragments entered Earth's orbit, and one — 50 miles across, roughly the size of Boston — slammed into the coast of Mexico.