Astronomers were shocked in recent days when an asteroid that some are calling a “city-killer” passed last week within 45,000 miles of Earth — spitting distance in astronomical terms.
Ground-side observers had been tracking a couple of celestial objects that were slated to cross near Earth’s orbit around the same time, but the hunk of space debris, estimated to be between 57 and 130 meters (187-426 feet) wide, was only detected hours before it streaked past Earth on Thursday.
Speaking with the Washington Post, Alan Duffy of the Royal Institution of Australia said that he “was stunned” and that the sudden appearance of the object, dubbed Asteroid 2019 OK, “was a true shock.” It passed “uncomfortably close,” he said.
As it sped past the Earth the space rock was traveling at 54,000 miles per hour.
— ASAS-SN (@SuperASASSN) July 25, 2019
Astronomer Michael Brown told the US paper that the asteroid had come “out of nowhere” and that it “snuck up on us pretty quickly.”
“People are only sort of realizing what happened pretty much after it’s already flung past us,” he said. “It shook me out my morning complacency. It’s probably the largest asteroid to pass this close to Earth in quite a number of years.”
According to Duffy, if it had hit “it would have gone off like a very large nuclear weapon.”
According to MIT Technology Review, the asteroid’s “relatively small size, unusual orbit, and fast speed all conspired to make it tough to spot.”
“Mostly, we keep an eye out using Earth-based telescopes,” the publication explained. “A space-based infrared telescope designed specifically for the purpose of spotting asteroids would be better for early detection, according to NASA. So the agency plans to launch the Near Earth Object Camera in 2021.”
An asteroid smaller than 2019 OK injured hundreds and damaged a synagogue when it hit Siberia in 2013. At the time, the Russian Academy of Sciences said in a statement that the meteor over the Chelyabinsk region entered the Earth’s atmosphere at a speed of at least 54,000 kph (33,000 mph) and shattered about 30-50 kilometers (18-32 miles) above ground.
People may be most familiar with the concept of asteroid strikes from films like 1998’s “Armageddon” and “Deep Impact.” While film heroes have stopped killer asteroids by using nuclear weapons and other tactics, those working on the issue in real life at places like NASA take a slightly different tack.
According to the American space agency’s website, “if an approaching asteroid were detected early enough, it could be possible to divert its path using the gravity of a spacecraft. Instead of sending an impactor to ram into an approaching object, a gravity tractor device would fly alongside the asteroid for a long period of time (years to decades) and slowly pull it out of Earth’s path.”