In July of 2005 we shot and hit a Comet and blew a hole in the side. Jet propulsion Laboratories then watched the debris as it spun off into space. With this we discovered the materials it is made up of and will use this information to determine what damage, if any such a Comet or large Asteroid might do to Earth if it hit our planet. By knowing what it consisted of and the type of material we can model how much would be melted by our atmosphere on entry and how much would hit our surface. Project Deep Impact smashed into the fast moving body and gave humans a first look inside an actual Comet;

http://deepimpact.jpl.nasa.gov/home/index.html

In November of 2005 Japanese Scientists came close and some say landed on the (Hideo) Itokawa Asteroid with their Hayabusa (falcon) Probe. The close up photos have helped scientists learn more about what asteroids are made of.

In 2006 proposals will be brought forth using all this data to come up with ways to prevent Earth strikes of near earth objects. Some of these proposals will call for shooting down object made of ice, deflecting heavy metallic objects or attaching self generating propulsion systems to move their trajectory for next time around. Others in the privatization of space will want to mine them for their mineral value. All these ideas and more are going to be floated as solutions, so keep your mind on this in 2006.