NASA's Asteroid Redirect Mission Aims to Save the Earth from Possible Asteroid Strikes by 2021
John Holdren, chief science advisor to President Obama, claims that our planet could be hit by an asteroid and it could bring about catastrophic consequences. An asteroid is anything that orbits the sun and is not big enough to be a planet. They might be dangerous if an asteroid big enough hits the Earth. Read on to find out more about asteroids and how NASA plans to take care of any threats.