It has also become apparent that some asteroids could pose a threat to Earth. Here are the ones we should be concerned about. You will note that the one named Apophis should be of special interest. At least some astronomers have dedicated themselves to identifying and tracking potential impactors. We have a scale that expresses the possibility of an asteroid impact, although no object has yet to cause any serious concern. There is a newer, more technical, hazard scale called the Palermo Scale. So what would happen if one of these objects actually impacted Earth? We are certain that a very large object hit off the coast of Mexico 65 million years ago. This was the Chicxulub event. As recently as nine years ago, we found out that we are still at risk when a rather large object hit Russia. With great dramatic effect! Could there be another catastrophic event in the near furture? Do we have anything to worry about?