With each passing day of the exercise, the participants learned more about the asteroid's size, trajectory, and chance of impact. Then they had to cooperate and use their technological knowledge to see if anything could be done to stop the space rock.
The experts fell short. The group determined that none of Earth's existing technologies could stop the hypothetical asteroid from striking given the six-month timeframe of the simulation. In this alternate reality, the asteroid crashed into eastern Europe.
As far as we know, no asteroids currently pose a threat to Earth in this way. But an estimated two-thirds of asteroids 460 feet in size or bigger — large enough to wreak considerable havoc — remain undiscovered. That's why NASA and other agencies are attempting to prepare for such a situation.