'Nova' asteroid could rock your world in '36

Don't worry about this one. We won't last that long.

A projected trajectory shows the asteroid, Apophis (named for the Egyptian god of death and darkness), will come very close to our planet in 2029, and have a chance of hitting Earth on its next pass in 2036.

If it hits, the impact would equal the force of 100 nuclear bombs, said Tyson, the new host of "Nova scienceNOW." The show will devote a segment of its Oct. 3 season premiere to "doomsday asteroids."

Tyson says we have plenty of time to act, react and reassess. "In 2029," Tyson said, "on Friday the 13th in April, Apophis is a certainty to come closer to Earth than our communications satellites. It'll be the largest thing to come that close in recorded history ... and depending on that trajectory, will determine whether it will hit us seven years later."