Asteroids smaller than those now being actively catalogued constitute a largely neglected natural hazard
by Russell Schweickart, Clark Chapman
In October 2001, we and 22 like-minded engineers and astronomers, including a few former and current astronauts, got together at the Johnson Space Center in Houston to discuss what we saw as a missing element in the space program: attention to the possibility of our planet being struck by a near-Earth asteroid. We knew of the accelerating rate at which such objects were being discovered. But no one, certainly no federal or international agency, was taking seriously the question of what exactly to do when an asteroid is found with our address on it.
During that initial meeting, less than six weeks after the 9/11 terrorist strike, we decided that this threat from outer space needed to be dealt with seriously and that our group might just be able to move the process along. To facilitate our work, we formed the B612 Foundation, a non-profit corporation named after the home asteroid of the title character in Antoine de Saint-Exupéry’s The Little Prince.
NASA has been spending about $4 million a year to meet a 1998 Congressional mandate to chart (by 2008) at least 90 percent of the near-Earth asteroids that are more than 1 kilometer in diameter. NASA’s Jet Propulsion Laboratory has been overseeing the effort, called the Spaceguard Survey, which has to date discovered more than 790 of an estimated 1,100 or so of these huge, rocky objects. The impact of a 1-kilometer asteroid would release the same amount of energy as 70,000 megatons of TNT or, equivalently, as 1,400 of the largest thermonuclear weapons ever detonated. The subsequent Sun-dimming pall of debris lofted high into the atmosphere would envelop our planet for months, threatening all of human civilization…