The following HTML text is provided to enhance online
readability. Many aspects of typography translate only awkwardly
to HTML. Please use the page image as the authoritative form to
ensure accuracy. Defending Planet Earth: Near-Earth-Object
Surveys and Hazard Mitigation Strategies or regional effects
near the time and place of the impact, but could include, for
large impacts, global climate change or tsunamis. But how large
an impact and what kind of impact could cause these effects is
still uncertain. A research program is needed to address all of
these issues in order to assess and quantify the risks
associated with the NEO impact hazard. The ability to mitigate
the impact hazard, or even to define appropriate strategies for
mitigating the hazard, likewise depends on the acquisition of
the new knowledge and understanding that could be gained through
a research program. Even if the only viable mitigation approach
to an impending impact is to warn the population and to
evacuate, better information is needed