Asteroid Impact 

Long time ago. in mesozoic era. a huge asteroid crashed on earth. the asteroid impact caused a mass extinction. many species were killed. such as dinosaurs. asteroid that is 1km long, it strikes the earth every 500,000 years. and in 1994 a asteroid crashed in Jupiter. someone calculated that there is a probability that a 1km asteroid will crash in earth in march 2880. but there are also sayings that earth will end at 2012.small asteroids hits earth 3 times in a century. in Siberia in 1908, June 30th, a explosion appeared on the sky. it was a asteroid impact.

the asteroid impact killed the dinosaurs because when the asteroid hit the earth 65 millions ago. it made the environment change. like it made it hot. but some species survived. like 5 percent. and the asteroid caused dust on the air. i think asteroid impact can cause a huge damage. 

this picture is from google                                                                     

this picture is from google                                                                     

                                                                                                                                         this picture is from google