As you may have read, our home planet will have a close call tomorrow, February 15, with a 180,000 ton asteroid called 2012 DA14. There is no chance of a collision, but the space rock will come within 17,200 miles, closer than many of our communication satellites.
You can follow the approach of the asteroid tomorrow from several of the Southern Stars apps for iOS. You won't be able to see the asteroid with the naked eye -- that will take a pretty large telescope with computerized tracking to get it into the correct position -- but SkySafari Plus and SkySafari Pro