A newly discovered car-sized asteroid just made the closest-known flyby to Earth without hitting our planet.
On Sunday (Aug. 16), the asteroid, initially labeled ZTF0DxQ and now formally known to astronomers as 2020 QG, swooped by Earth at a mere 1,830 miles (2,950 kilometers) away. That gives 2020 QG the title of closest asteroid flyby ever recorded that didn't end with the space rock's demise.
It's the closest known, non-impacting asteroid, NASA officials told Space.com
Video: See asteroid 2020 QG's orbit around the sun!
Related: Potentially dangerous asteroids (images)
The flyby wasn't expected and took many by surprise. In fact, the Palomar Observatory didn't detect the zooming asteroid until about six hours after the object's closest approach. "The asteroid approached undetected from the direction of the sun," Paul Chodas, the director of NASA's Center for Near Earth Object Studies, told Business Insider. "We didn't see it coming."
Related: Famous asteroid flybys and close calls (infographic)
"Yesterday's close approach is [the] closest on record," Chodas told Business Insider. "If you discount a few known asteroids that have actually impacted our planet."
The close flyby was also a fast one, as 2020 QG swooped near Earth at a blistering 27,600 mph (44,400 kph). The object is about the size of a compact car, perhaps about 10 to 20 feet (3 to 6 meters) in diameter.
According to the International Astronomical Union's Minor Planet Center, 2020 QG flew over the Pacific Ocean, far east of Australia, during its close approach. To explore the daredevil asteroid for yourself, you can check out NASA's Jet Propulsion Laboratory's small-body database browser here.
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I think that if they get much closer than that (not sure how close), they get caught in Earth's gravity and are pulled in. I don't know any of the math, but I'm sure angle of approach as well as velocity play into whether it misses or gets caught.
Semi-major axis is 1.9138 AU, e = 0.487, period = 2.68 years. The asteroid perihelion distance is near 0.99 AU.
I would assume the closest fly-bys would be those that skip off the atmosphere. The Shuttle needed about a 40 deg. approach angle to avoid skipping off, IIRC. Perhaps asteroids are less aerodynamic, but even a round rock would skip off water if thrown fast enough and low enough.
I was thinking the same thing. US19720810 "1972 Great Daylight Fireball" was a lot closer. This might even be the same rock, that might have been here again in 1997. But why does the news reports keep saying that 2020 QG was the closest ever?