Chapter 9, Problem 35EAP

Assessing Impact Danger. Roles: Scribe {collects data and takes notes on the group's activities), Proposer (proposes hypotheses and explanations of the data), Skeptic (points out weaknesses in the hypotheses and explanations}, Moder:ator (leads group discussion and makes sure everyone contributes). Activity: Assess the risks we face on Earth from meteorite and comet impacts as follows.

1. Consider the question of the odds that human civilization will be destroyed by an impact during your lifetime. Determine the kinds of information you would need, develop a method for making the estimate, and write down your method.
2. Analyze Figure 9.27 1£1and determine whether it contains any of the necessary
information.
3. App ly your group's method to estimate the probability that civiliza,tion will be destroyed by an impact during your lifetime, which you can assume to be 100 years for the purpose of this exercise.
4. Estimate the probability that an impact will cause "widespreaddevastation" somewhere on Earth during your lifetime.
5. Finding near-Earth asteroids earily greatly increases our chances of deflecting them. Given the probabliities from parts c and d and cons idering the damage these events would cause, decide as a group how much money per year should be spent on finding near-Earth asteroids and explain your reasoning.