Scientists are always on the look out for asteroids in our solar system. Check out NASA’a asteroid and comet watch: http://www.nasa.gov/asteroid-and-comet-watch/
It is speculated that a large asteroid hitting the Earth caused the extinction of the dinosaurs. Could an asteroid be a future threat to Earth? Scientists believe that the chance of a large asteroid lining up to hit Earth is extremely rare and nothing has been found through space observations to pose a current or future threat. But just in case, scientists continue to think about ways to stop an asteroid. Their ideas include: blowing it up with a nuclear bomb, strapping large rockets to it or gently guiding it away with solar sails.
What would you do? Tell us in the comments below
FYI: what is the difference between an asteroid and a meteor?
In space, a large rocky body in orbit about the Sun is referred to as an asteroid whereas much smaller particles in orbit about the Sun are referred to as meteoroids.
Once a meteoroid enters the Earth’s atmosphere and vaporizes, it becomes a meteor (i.e., shooting star).