Visit science.nasa.gov/ for more. The New Year started off with a bang when a small asteroid hit Earth. Infrasound records indicate that the space rock exploded in the atmosphere over the Atlantic Ocean like 500 tons of TNT.
Depends on the composition of the meteorite(iron,silicone,etc.)and where it came from.1kg of ordinary space rock will set you back about 1000$ to 6000$,but a meteorite from the moon or mars will buy you a new house or ten :D
That's for small space rocks. .. There have been whole sky surveys (such as WISE) searching for *_large_* 'near-Earth' asteroids that could cross our path sometime in the distant future. .. "NASA has found more than 90 percent of the largest near-Earth asteroids, meeting a goal agreed to with Congress in 1998." www.nasa.gov/mission_pages/WISE/news/wise20110929.html ... "No one should be overly concerned about an Earth impact of an asteroid or comet. The threat to any one person from auto accidents, disease, other natural disasters and a variety of other problems is much higher than the threat from Near Earth Objects." neo.jpl.nasa.gov/neo/target.html
