One day after NASA told a House committee that advice on how to handle a large asteroid headed to New York City, was to "pray", a group of scientists echoed those sentiments at a hearing before the Senate Committee on Commerce, Science, and Transportation on Wednesday (March 20th).
"I just again want to point out that there is a 30-percent chance that there is a 5-megaton or so impact that's going to happen in a random location on this planet this century, so this is not hypothetical," said former astronaut and CEO of B612 Foundation, Dr. Ed Lu.
An asteroid estimated to be have been about 55 feet (17 meters) in diameter exploded on Feb. 15 over Chelyabinsk, Russia, generating shock waves that shattered windows and damaged buildings. More than 1,500 people were injured.
Later that day, a larger, unrelated asteroid discovered last year passed about 17,200 miles (27,681 km) from Earth, closer than the network of television and weather satellites that ring the planet.
NASA has found and is tracking about 95 percent of the largest objects flying near Earth, those that are .62 miles (1 km) or larger in diameter.
But only about 10 percent of an estimated 10,000 potential "city-killer" asteroids, those with a diameter of about 165 feet (50 meters) have been found, according to White House science advisor John Holdren.
Lu, who flew two times on American space shuttle flights and spent six months on the International Space Station, said technology exists that may prevent impacts from asteroids, but years of advance notice is required.
"If you change an asteroid's speed by something like a millimetre per second, that's about the speed that an ant walks, and you do that 10 years or more decades before it's going to hit the Earth, you can make it miss the Earth. So that means, all you basically really need to do is either run into it with a small spacecraft, it's called a kinetic impactor. You can tow them gravitationally using a small spacecraft called a gravity tractor. For the very larger ones, the kilometre size ones you can use a nuclear standoff explosion. These are all technologies that we believe we know how to do. They key is, if you don't know where they are, there is nothing you can do. If you have less than a few years notice, right now, we have no option," he said.
Lu is currently the CEO of the B612 Foundation, a nonprofit group that advocates action to prevent asteroids from hitting earth. The company is working on a project to launch a space telescope to track all the asteroids in the inner solar system.
The asteroid that exploded over Russia last month was the largest object to hit Earth's atmosphere since the 1908 Tunguska event when an asteroid or comet exploded over Siberia, levelling 80 million trees over more than 830 square miles (2,150 sq km).
Presented by Adam Justice