Seventh Circuit Court of Appeals Judge, law professor, economics and law guru, and author Richard Posner has written — in light of the recent Indian Ocean Tsunami disaster — a timely new book, Catastrophe: Risk and Response (Oxford, Oct. 1, 2004), in which he argues that governmental planning for even unlikely disasters makes economic sense. Peter Singer reviews Judge Posner’s new book here.
Judge Posner summarizes his argument in that regard in this Wall Street Journal ($) op-ed, and makes the following point that should give pause to those who advocate further cuts in NASA’s budget:

An even more dramatic example [of lack of planning for unlikely disasters] concerns the asteroid menace, which is analytically similar to the menace of tsunamis. NASA, with an annual budget of more than $10 billion, spends only $4 million a year on mapping dangerously close large asteroids, and at that rate may not complete the task for another decade, even though such mapping is the key to an asteroid defense because it may give us years of warning. Deflecting an asteroid from its orbit when it is still millions of miles from the earth is a feasible undertaking. In both cases, slight risks of terrible disasters are largely ignored essentially for political reasons.
In part because tsunamis are one of the risks of an asteroid collision, the Indian Ocean disaster has stimulated new interest in asteroid defense. This is welcome. The fact that a disaster of a particular type has not occurred recently or even within human memory (or even ever) is a bad reason to ignore it. The risk may be slight, but if the consequences, should it materialize, are great enough, the expected cost of disaster may be sufficient to warrant defensive measures.