If scientists detected a major asteroid headed for Earth now, it would take at least five years and billions of dollars to develop an effective defense system to either alter its course or destroy it, scientists say.
CNN.com - Top Stories, CNN
Tue, 03/19/2013 - 2:01pm
If scientists detected a major asteroid headed for Earth now, it would take at least five years and billions of dollars to develop an effective defense system to either alter its course or destroy it, scientists say.