The U.S. government is stepping up efforts to protect the planet from incoming asteroids that could wipe out entire regions or even continents.
The National Science and Technology Council recently released a report calling for improved asteroid detection, tracking and deflection. NASA is participating, along with federal emergency, military, White House and other officials.
NASA’s planetary defence officer, Lindley Johnson, said scientists have found 95% of all these near-Earth objects measuring one kilometre or bigger. But the hunt is still on for the remaining 5% and smaller rocks that could still inflict big damage.
Altogether, NASA has catalogued 18,310 objects of all sizes.
There’s no quick solution if a space rock is suddenly days, weeks or even months from striking, according to Mr. Johnson.
Emergency planning
But such short notice would give the world time, at least, to evacuate the area it might hit, he said.
Ground telescopes are good at picking up asteroids zooming into the inner solar system and approaching from the night side of the earth, Mr. Johnson said. What’s difficult to detect are rocks that have already zipped past the sun and are heading out of the solar system, approaching from the day side.
That’s apparently what happened in 2013 when an asteroid about 66 feet in size suddenly appeared and exploded over Chelyabinsk, Russia, damaging thousands of buildings and causing widespread injuries.
