It accurately estimated most aspects of the Chelyabinsk impact in a retroactive test, including strike zone, atmospheric blast wave and ground shaking, but was slightly off in estimates of how far the air blast would reach and shatter windows within the city, he said.
Melosh is working to better understand and calculate this effect in a city environment and to improve the precision of other calculations.
"It wouldn't take a large amount of money to create civil defense plans for the unlikely event of a small meteor strike," he said. "For larger meteors that would require a more proactive defense, improved surveillance could give us a century of advance notice and plenty of time to create and deploy a deflection tool."
In addition to his expertise in the effects of asteroid impacts, Melosh has been involved in asteroid deflection research for years. He was a co-investigator on NASA's 2005 Deep Impact mission, which successfully targeted and hit a comet with a spacecraft. He also developed an approach to deflect an asteroid through the evaporative effects of focused sunlight in 1993. A paper detailing this work was published in the Nov. 4, 1993 issue of "Nature."