WASHINGTON – The White House and NASA are asking the public for help finding asteroids that potentially could slam into the Earth with catastrophic consequences.
Citing planetary defense, the administration has decided that the search for killer rocks in space should be the latest in a series of “Grand Challenges,” in which the government sets an ambitious goal, helps create public-private partnerships and sometimes offers prize money for innovative ideas.
“This is really a call to action to find all asteroid threats to human populations and know what to do about them,” NASA Deputy Administrator Lori Garver said. She said the asteroid hunt would help prove that “we’re smarter than the dinosaurs.”
There is a second agenda at work here. The NASA human spaceflight program needs to find a target rock for the Asteroid Redirect Mission (ARM). The proposed mission, which is early in the planning stages, would send astronauts to visit an asteroid that had been redirected into a high lunar orbit. But first a robotic spacecraft would have to rendezvous with the asteroid and capture it. And even before that, scientists would have to find the right asteroid.
The target rock has to be moving at a leisurely pace relative to the Earth, and ideally would come close in the early 2020s. At present, NASA has a short list of possible targets, but all need further scrutiny to see if they have the size, shape, spin rate and composition that the asteroid mission would require.
Two recent feasibility studies used as their reference a rock discovered in 2009, but NASA scientists aren’t sure that it will meet the mission requirements. For one thing, it might turn out to be too small. They plan to study it this fall with the Spitzer Space Telescope.
But NASA scientists are clearly eager to speed up the rate of discovery of small asteroids, and thus expand the pool of candidate rocks for the ARM mission.
Thanks to a number of asteroid searches in the past 15 years, about 95 percent of the near-Earth objects larger than 1 km in diameter have already been detected, and their trajectories calculated. None poses a significant threat of striking the Earth in the foreseeable future.