One thing that asteroid and comic movies miss (or play up for dramatic effect) is the reality that the Earth is pelted by space junk on a consistent basis. Cosmos Magazine reports that about 6,100 meteors that are large enough to reach the ground strike the planet every year — resulting in roughly 17 collisions every day. Often, these go unnoticed because the majority of the Earth’s surface is covered in water, and vast swaths of land remain uninhabited — even as humans continue to spread out across the planet. Indeed, the University of Texas estimates that around 57% of the Earth’s land area remains uninhabited.
In truth, this is all simple science. Space is filled with debris of all sorts, and an even larger number of particles pass close enough to be burned up in Earth’s atmosphere without ever being noticed by the layperson. Added to this reality, NASA reports that no known asteroid or comet that could cause significant harm to human life has been identified to be on a collision course with the planet, but they also admit if there was an Earth-killing asteroid, you wouldn’t have time to tweet about it. Science Norway estimates that these types of life-threatening collisions might happen roughly once every 100 million years.