Asteroid Apocalypse? "Nation-busting" asteroid could hit earth in 2036

Physicist Michio Kaku says an asteroid powerful enough to destroy nations is on a collision course with earth.

A much smaller one exploded just above Russia last week - its power was equal to 20 Hiroshima bombs.

Kaku says the nation-busting asteroid headed our way won't arrive until 2036, but it could make a direct hit with 1000 times more power - that's 20,000 Hiroshima bombs.

OutFront tonight: Bill Nye "The Science Guy" and former astronaut Rusty Schweickart.