Killer Rocks

摘要

The sky is falling. Or so it seemed on March 11, when astronomer Brian Marsden of the Harvard-Smithsonian Center for-Astrophysics announced that a mile-wide asteroid might pass within 30,000 miles of Earth in the year 2028. Marsden said there was even a slight possibility that the asteroid now known as 1997 XF11 might collide with Earth at that time.