Car-sized asteroid zooms past Earth at about 8 miles per second, scientists call it closest flyby ever detected
A comparatively small, SUV-sized asteroid quietly whizzed by the Earth over the weekend. Despite the close encounter, it failed to hit the planet. Even if it did, the space rock was too small to inflict any significant damage, experts have said.
The object named 2020 QG, measures 10 to 20 feet, which is very small by "asteroid standards", according to NASA, which learned of the flyby only after it flew past Earth. It passed less than 3,000 kilometers from the planet above the southern Indian Ocean on August 16 at 12:08 a.m. EDT.
It is the closest approach made by a non-impacting asteroid. "The asteroid approached undetected from the direction of the sun," Paul Chodas, director of the Center for Near-Earth Object Studies (CNEOS) at NASA's Jet Propulsion Laboratory in Southern California. told Business Insider. "We didn't see it coming," he added.
Chodas explained that tiny close-in asteroids travel at high speeds and detecting them was an accomplishment in the first place. "There's typically only a short window of a couple of days before, or after close approach when this small of an asteroid is close enough to Earth, to be bright enough, but not so close that it moves too fast in the sky to be detected by a telescope," he said in a statement.
It was zooming at about 8 miles per second (12.3 kilometers per second). Observing the space rock was Zwicky Transient Facility, an astronomical survey at the Palomar Observatory in California. It was detected only six hours after the flyby. Later two European observatories targeted this asteroid. "It was the closest asteroid ever observed to pass by our planet without hitting it, and the fifth closest overall, if we include the four small asteroids that actually impacted," the European Space Agency said in a statement.
"It's really cool to see a small asteroid come by this close because we can see the Earth's gravity dramatically bend its trajectory," Chodas said. "Our calculations show that this asteroid got turned by 45 degrees or so as it swung by our planet."
Its size also meant that it was too small to have caused devastation. A more probable scenario, according to NASA, would be the asteroid turning into a fireball as it passed through the Earth's atmosphere. "Objects causing fireballs are usually not large enough to survive passage through the Earth’s atmosphere intact, although fragments, or meteorites, are sometimes recovered on the ground," the Center for Near-Earth Object Studies said.
Near-Earth objects are asteroids or comets whose sizes vary from meters to tens of kilometers. The 1908 Tunguska event on the remote Siberia in Russia is attributed to an asteroid impact. The blast tore apart eight hundred square miles of remote forest, affecting eighty million trees.
NASA is tasked with detecting 90% of near-Earth asteroids that are about 460 feet (140 meters) or larger. If they were to impact the planet, it would lead to massive damage. "They can be detected much farther away from Earth because their rate of motion across the sky is typically much smaller at that distance," NASA said.