CNN CNN Newsroom Live November 21, 2021 08:55:00
In the end the planet survives. a hollywood ending which nasa is hoping to make a reality with its first planetary defense test mission. scientists say they have identified the kilometer wide asteroids like those shown in the block busters, and there are no darngers of them hitting earh in the coming centuries. but nasa says it wants to study what could be done if an earth threatening asteroid is discovered. on wednesday it will launch a mission called dart, the double asteroid redirection test, that will send an unmanned spacecraft into space, and if successful, it won't be returning home. da...