For NASA it seems not to be that frightening. We believe that Dr. Wenning's data is accurate. After all, there are believed to be at least 2,000 NEO' s in space that could pose a threat to our existence on this Earth. Although scientists think that there are 2,000 NEO's only 200 have really been discovered. It is the other 1,800 or so that Dr. Wenning is worried about the most.
Some scientists say that an impact with an asteroid is very likely.
NASA and the majority of scientists do not believe that claim. We believe that an asteroid collision is very possible. An asteroid that size would cause considerable life and property damage if it would hit in a urban area. Consider further if a 500 m asteroid hit the earth. That doesn't seem that big, but , according to Bob Hawkes, it would devastate an area the size of Quebec and Ontario, Canada combined.