NASA recently announced the discovery of ten “potentially hazardous” asteroids close to Earth. These space rocks are in the Taurids, a cluster of asteroids and meteors that produce an annual meteor shower visible on earth in late October and early November. The discovery was made by NASA’s asteroid-detecting satellite NEOWISE, which stands for Near-Earth Object Wide-field Infrared Survey Explorer.
Keith Cowing, editor of nasawatch.com, says this is exactly the sort of thing NEOWISE has been looking for. “The fact that they found them isn’t surprising,” he says. “The number, though, and the vicinity with which they come close to the earth, did surprise a few people.”
Cowing points out that these potentially dangerous objects don’t need to be very big. “Even something the size of a lunchbox,” he says, because of the speed involved, “can cause a lot of damage,” depending on where it hits.
Cowing continues, “It doesn’t take much in terms of size for one of these things to be very hazardous,” he says. “The one that came in over Russia a few years back wasn’t exceptionally big. I believe you could probably put the thing in your front yard.”
The Chelyabinsk meteor exploded in the atmosphere over Russia in February 2013 at a speed of at least 40,000 mph. “It was an airburst, and it was rather high up, luckily for everybody who was underneath it,” Cowing notes. “But the concussion of just that explosion many miles up was enough to cause the damage that you saw.”
Cowing says we probably know about only a fraction of earth strikes by space rocks. “These things probably do happen a bit more often than we know,” he says, “because the earth is mostly water, a lot of it is still uninhabited, and so things do come in regularly.”
He says people are right to be concerned about the danger represented by a possible asteroid impact, but he says they should keep the risk in perspective. “Is metropolitan commuting in Houston more dangerous than asteroids?” he asks. “I would wager that driving to work every day is probably a little more dangerous.”