Space agencies from around the world are running simulations of how the world would respond to a massive asteroid strike. In the past week, experts from NASA and the European Space Agency pretended that New York City was destroyed. It's an annual exercise held at the International Academy of Astronautics Planetary Defense Conference. Last year, the group saved Tokyo from disaster by launching a nuke at the space rock. This time, efforts were less successful and in an effort to deflect the asteroid from hitting Denver, they knocked a piece off course into New York. The city was destroyed, but they had some time to evacuate millions of hypothetical residents before impact.