NASA's charter has also been changed explicitly to include a responsibility to provide advance warning of potentially damaging asteroid impacts.

ECONOMIST: The American Association for the Advancement of Science

Once the sun and planets took shape, heat became readily available in the form of solar radiation, asteroid impacts, and gravitational pressure.

ECONOMIST: Minerals

And long-term human settlement will follow at some point, mainly to develop mineral and energy resources available on the Moon, but also to emplace protective systems aimed at avoiding large asteroid impacts of the type we were all recently made aware with that grazing meteor strike in Chelyabinsk and the simultaneous near-miss by big-rock DA14.

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That survey was requested by America's Congress nearly a decade ago, and was stimulated in part by the dramatic images of Comet Shoemaker-Levy, whose collision with Jupiter in 1994 generated a great deal of public awareness of the risk of asteroid impacts. (A couple of Hollywood films exploring doomsday scenarios also swayed opinion.) In 2005 Congress ordered the survey that is about to start.

ECONOMIST: The American Association for the Advancement of Science