Do you live in daily fear of a large asteroid causing an extinction event on your home planet?
You shouldn't, you'll get nothing done.
And if you do, or feel by reading this you're about to, then we're about to really help you along that road.
Here's a Nasa/JPL-Caltech illustration of the orbits of potentially hazardous asteroids:
If you really want to scare yourself, take a look at the Near Earth Object Program - 20 objects are supposed to approach earth during the remainder of January.
There are over 1,000 asteroids defined as potentially hazardous, meaning they could one day affect life on earth.
None of them will strike Earth in the next 100 years, based on calculations of their orbits - but not all Potentially Hazardous Asteroids (PHA) have been identified.,
Purdue University have made an asteroid simulator, which you can fiddle with to find out how asteroids of varying size, speed, density and impact angle, would affect the planet.
It's all good, clean fun.