Planetary securityAsteroid collision: How to defend Earth, II
Asteroid impacts are much rarer than hurricanes and earthquakes, but they have the potential to do much greater damage; moreover, what if an asteroid hits Earth in the Middle East or the Asian subcontinent? Such an event could be misinterpreted as a nuclear attack — both produce a bright flash, a blast wave, and raging winds; the result may be a nuclear war
There are thousands of Near Earth Objects (NEOs) orbiting our planet, with scientists defining some 800 of them as “hazardous,” that is, they are close enough and large enough — and their trajectory indicates that they might get even closer to Earth — to pose a real threat to Earth (see 12 October 2009 HSNW).
There are those who suggest that the superpowers coordinate among them the creation of a nuclear strike force, the sole mission of which would be to blast dangerous asteroids if they appear to be getting to close to Earth.
David Shiga writes that, realistically, the nuclear option would not be on the table in the first place: the nuclear-tipped missiles sitting patiently in silos around the world are not designed to track and home in on an asteroid or even survive for more than a few minutes in space. Instead, we would simply have to brace ourselves for the impact.
Avoiding panic
The good news, Shiga notes, is that even a little warning makes a big difference because it would allow us to predict the time and location of impact. In the case of 2008 TC3 (see 10 October 2008 HSNW), just a few hours after the asteroid’s discovery, NASA scientists completed calculations that predicted an atmospheric plunge over an unpopulated desert area of northern Sudan, with timing accurate to within a minute.
Participants in the planning exercise worried that if an asteroid posing an imminent threat to a populated area were discovered, and the situation were not handled properly, panic and lack of coordination could lead to chaos on the roads.
Timothy Spahr, director of the Minor Planet Center in Cambridge, Massachusetts, was not involved in the exercise, but shares those concerns. “With a three-day warning, you can walk away and be safe. But it scares me, given how poorly we’ve handled things of this nature in the past,” he says, citing the failure to fully evacuate New Orleans ahead of hurricane Katrina in 2005. “I’m picturing people panicking and driving the wrong way on the freeway, screaming ‘Oh my god, it’s going to kill us!’”
Shiga says that to prevent panic and disorganized movement, it is crucial for authorities to develop an evacuation plan and communicate it to the public as soon as possible after discovery of the dangerous object, since such discoveries are posted automatically online and would cause a media firestorm.
Such measures should ensure the streets would be very quiet as
