Telescopes needed to detect asteroids before they hit Earth, panel told
For every asteroid that has been detected, there were probably 100 more that have not been seen, including hundreds of thousands that are the size of the meteor that exploded in Russia last month, an expert says.
The New York Times
Making a case for the need to detect asteroids before they hit Earth, a former astronaut said Wednesday that the number of casualties would have been enormous had the space rock that exploded in Russia last month blown apart directly over New York City instead.
“We’d have a lot more than broken windows, that’s for sure,” the former astronaut, Edward Lu, told a Senate panel in Washington.
Lu, also a former Google executive, is now the chief executive of the B612 Foundation, a Silicon Valley group that wants to build a privately financed asteroid-detecting space telescope.
About 1,500 people were injured when the roughly 60-foot-diameter meteor exploded high in the atmosphere near the Russian city of Chelyabinsk on Feb. 15. Most of the injuries were caused by flying glass from shattered windows when a shock wave from the explosion — estimated to have been about 30 times more powerful than the atomic bomb that destroyed Hiroshima — hit the city a minute and a half later.
“Had that shock wave been a lot closer to a city, it would have caused a lot more damage,” Lu said.
The Chelyabinsk meteor was not detected by any of the ground-based telescopes, operated by NASA and others, that are surveying the sky for space rocks that are in orbits that could intersect with Earth’s.
Those search programs are focused on larger asteroids, James Green, director of the planetary science division of the National Aeronautics and Space Administration (NASA), told the Senate panel, the Science and Space Subcommittee.
So far about 10,000 have been detected, including about 95 percent of the estimated 1,100 that are a kilometer (about 1,000 yards) or more in diameter and have the potential to end civilization. So far, Green said, no asteroid has been found that poses a threat to the planet.
But Lu noted that for every asteroid that had been detected, there were probably 100 more that had not been seen, including hundreds of thousands that are the size of the Russian meteor.
“Right now, the amount of warning time that we are likely to get from one of these asteroids is zero,” he said.
In response to a question from Sen. Ted Cruz, of Texas, the ranking Republican on the subcommittee, Lu said that given enough lead time, there were various ways to divert an asteroid to make it miss Earth entirely, including something as basic as running into it with a spacecraft to nudge it just a bit.
“I’m eager for our collective journey to ensure that NASA and all related programs have sufficient resources and sufficient priorities to do what needs to be done,” said Cruz, who was elected last year with tea-party backing, in his opening remarks.
Asked after the hearing about the senator’s position on the NASA budget, only a small portion of which goes toward asteroid detection, a spokeswoman for Cruz said she had no comment.