016.4 Hunting Killer Asteroids
How our picture of the inner Solar System has evolved (images courtesy of the Armagh Observatory):
In June, 1999, an international conference on near-Earth objects was held in Turin Italy. The conference participants voted to use the following "Torino Scale" to describe threats from these objects.
Notice that the Tunguska event, the 1996 Greenland event and the 2002 explosion over the Mediterranean Sea all would have been classified as "8" on the Torino Scale if we had been tracking the objects before they hit. These events are relatively frequent and are caused by objects that are much smaller than the ones we are tracking now.
For more information about the effort to find these objects, see:
NASA Spaceguard Survey
