The Case for Asteroid Defense

Should the United States be investing in asteroid defense? In an article in the* Atlantic*, Gregg Easterbrook argues that "improbable but cataclysmic dangers ought to command attention because of their scope." As an analogy, he notes, a "tornado is far more likely than an asteroid strike, but humanity is sure to survive the former. The chances that any one person will die in an airline crash are minute, but this does not prevent us from caring about aviation safety."

Of course, there are many things that pose a threat to human survival -- nuclear war, pandemics, and climate change -- and to some extent the investment in any defense should be proportionate to the risk. But Easterbrook's larger point -- that asteroid defense is more important than a loony lunar outpost -- is quite compelling. Easterbrook recaps the fundamental problem of the moon mission:

*As anyone with an aerospace engineering background well knows, stopping at the moon, as Bush was suggesting, actually would be an impediment to Mars travel, because huge amounts of fuel would be wasted landing on the moon and then blasting off again. Perhaps something useful to a Mars expedition would be learned in the course of building a moon base; but if the goal is the Red Planet, then spending vast sums on lunar living would only divert that money from the research and development needed for Mars hardware. However, saying that a moon base would one day support a Mars mission allowed Bush to create the impression that his plan would not merely be restaging an effort that had already been completed more than 30 years before. For NASA, a decades-long project to build a moon base would ensure a continuing flow of money to its favorite contractors and to the congressional districts where manned-space-program centers are located. So NASA signed on to the proposal, which Congress approved the following year. *

So Easterbrook concludes: "Wouldn’t shifting NASA’s focus away from wasting money on the moon and toward something of clear benefit for the entire world—identifying and deflecting dangerous space objects—be a surer route to enhancing national prestige?"

Well maybe. Identifying threats would tell us a lot more about whether we really need to be in the threat deflection business. And of course, there's always Alexander Bolonkin's city bubbles.