Asteroids hitting earth and destroying everything is nothing new, just ask the dinousaurs(:p). The probability of hit wiping out humanity just like it did the giant creatures is quite high and therefore NASA and other space agencies have been working on a system to tackle that asteroid before it is given the chance to destroy Earth. That system involves a simulation or a rehearsal of what it would be like to stop an asteroid from attacking Earth.
As per The New York Post, the scenario of a huge asteroid racing towards Earth at 31,000mph is supposed to be as realistic as possible and has been developed by a division of the NASA Jet Propulsion Laboratory that was tasked with studying near-Earth objects (NEOs).
According to Digital trends, With an average size ranging from 100-300 meters, the asteroid would be the first considered to have a 1 in 50,000 chance of colliding with Earth (in the vicinity of 0.002%), which later will rise to a 1 in 100 probability of impact. The exercise is to see how quickly and effectively the firms would react and what would be the best course of action. “These exercises have really helped us in the planetary defense community to understand what our colleagues on the disaster management side need to know,” said Lindley Johnson, NASA’s planetary defense officer. “This exercise will help us develop more effective communications with each other and with our governments.” “Although realistic, [this scenario] is completely fictional and does not describe an actual asteroid impact.”
It will be a week long rehearsal involving astronomers identifying the object and playing out a tabletop scenario in which an asteroid is dealt with. However, as mentioned earlier the researchers have clearly stated that it is merely a simulation and cannot be accurate enough to prepare for when it actually hits.