A large asteroid, impacting the world and leading to global catastrophe killed the dinosaurs. Since movies like Armageddon and Deep Impact, as well as documentaries on the Discovery Channel and other networks have been aired, people are more aware of the possibility of a "global killer" ending life on Earth. Tonight, we will experience a near-miss.

It wasn't a "Deep Impact," or "Armageddon," but asteroid 2009 DD45 came pretty darn close to hitting Earth on Monday.

The asteroid presumed to have wiped out the dinosaurs struck the Earth with such force that carbon deep in the Earth's crust liquefied, rocketed skyward, and formed tiny airborne beads that blanketed the planet, say scientists from the U.S., U.K., Italy, and New Zealand in this month's Geology.

Scientists say it has happened in the past and will happen in the future - a large, destructive asteroid strikes the earth. Mike O'Sullivan reports, an international competition by the Planetary Society in Pasadena, California, has offered ways to help assess the risk.