If a massive asteroid collides with Earth, it could end life on the planet as one knows it; new discoveries reveal just how close civilization is to apocalypse and what it would take for the world's leading space agencies to stop it. <br /><br />Thanks for watching. Follow for more videos. <br />#cosmosspacescience <br />#howtheuniverseworks <br />#season8 <br />#episode1 <br />#asteroidapocalypse <br />#asteroid <br />#comet <br />#spacetime <br />#space <br />#nasa <br />#astrophysice <br />#asteroidcollideswithearth <br />
