The year is 2020 and Los Angeles is about to be wiped off the face of the planet. You’ve known this day was coming since the fall of 2016, when the asteroid that is on a collision course with Earth was first discovered. At the time, the global consortium of scientists who’ve tasked themselves with saving Earth from giant asteroidsestimated that there was a 2 percent chance that the 800 foot-wide space rock would collide with Earth in late September of 2020. Nobody was particularly worried about it—Earth has had much closer brushes with annihilation before.
Yet as astronomers continued to track the asteroid after it was initially discovered, the probability of impact climbed to 65 percent by January of 2017. After a four month hiatus on observation while the asteroid was obscured by the sun, the astronomers resumed tracking the asteroid in May 2017 only to find that the probability of impact had jumped to 100 percent. It was now a question of where the asteroid would hit, not when or if it would hit. By November 2017, astronomers were able to conclude with some certainty that the asteroid’s trajectory would place the impact site near the coast of southern California.
This was the scenario laid out during a joint NASA-FEMA emergency planning meeting in late October. For now it remains a hypothetical, but one day it will be a reality.
“It’s not a matter of if—but when—we will deal with such a situation,” said Thomas Zurbuchen, Associate Administrator for NASA’s Science Mission Directorate in Washington. “But unlike any other time in our history, we now have the ability to respond to an impact threat through continued observations, predictions, response planning and mitigation.”