Highlights from the article below. Note, when you go the website of the article, they have an animation of the gravity tractor.
Scientists such as Stephen Hawking warn that their relatively close proximity presents grave dangers to humankind, a point of view supported in a number of recent books, such as William Burrows' The Survival Imperative: Using Space to Save Earth and British astronomer royal Martin Rees' Our Final Hour: A Scientist's Warning.
In December, NASA astronaut Edward Lu told Space.com that plans under study include landing on an asteroid and retrieving rock samples for return to Earth before 2020.
And at NASA's Ames Research Center, lab chief Simon "Pete" Worden, a longtime advocate of such exploration, has set aside $10 million for designing small spacecraft that could visit asteroids, according to the Jan. 19 Science magazine.
The space agency does have a few asteroid missions already planned. In its just-released 2008 budget, NASA said it is studying a mission, dubbed the Origins Spectral Interpretation, Resource Identification and Security (OSIRIS) probe, to return rock samples from an asteroid.
For something a bit sooner, [NASA scientist David] Morrison will describe a Near-Earth Asteroid Trailblazing (NEAT) probe, low-cost landers designed to flit among nearby asteroids, scouting their surfaces, at a March American Institute of Aeronautics and Astronautics meeting.
"Asteroids have been a low priority for too long," says Burrows, The Survival Imperative author, who calls for long-term space colonies to serve as a refuge for humanity if there's a catastrophic collision. "People worry about terrorism, with good reason, but while it doesn't do to get over-excited, there are bigger threats."
Asteroid defense gets a hearing next month at an American Association for the Advancement of Science symposium in San Francisco. With new telescopes in Chile and Hawaii coming online, astronomers expect Near-Earth asteroids to turn up nearly 100 times more often than today's rate of discovery.
Dan Vergano
USA TODAY
13 February 2007
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