An auto-sized asteroid named 2020 QG nearly hit Earth on Sunday

• An asteroid the size of a car flew this weekend within about 1,830 miles of Earth – closer than any known space rock has ever come without crashing into the planet.
• A NASA-funded program discovered the asteroid, named 2020 QG, six hours after its close approach.
• If the asteroid Earth had been hit, it would probably explode into the atmosphere in an air chest that was too high up to do damage to the ground.
• But the near miss marks a big blind spot in the Earth’s programs to search for dangerous asteroids.
• Visit the Business Insider website for more stories.

An asteroid in large cars flew about 1,830 miles (2,950 kilometers) from Earth on Sunday.

That’s a striking near shave – the closest ever recorded, in fact, according to asteroid trackers and a catalog compiled by Sormano Astronomical Observatory in Italy.

Because of its size, the space rock would probably not pose a danger to humans on the ground if it hit our planet. But the close call is nonetheless, because astronomers had no idea that the asteroid existed until after it passed.

“The asteroid approaches unexplored from the direction of the sun,” Paul Chodas, director of NASA’s Center for Near Earth Object Studies, told Business Insider. “We did not see it coming.”

Instead, the Palomar Observatory in California first discovered the space rock for about six hours no it flew through Earth.

Chodas confirmed the record-breaking nature of the event: “Yesterday’s close approach is the closest to record, if you short a few known asteroids that have actually affected our planet,” he said.

NASA only knows a fraction of near-Earth objects (NEOs) like this. Many do not cross the line of sight of a telescope, and several potentially dangerous asteroids have been knocked out by scientists in recent years. If the wrong slipped through the holes in our NEO surveillance systems, it could kill tens of thousands of people.

2020 QG flew over the southern hemisphere

This recent near-Earth asteroid was originally called ZTF0DxQ, but is now formally known to astronomers as 2020 QG. Business Insider first learned about it from Tony Dunn, the creator of the website orbitsimulator.com.

“Newly discovered asteroid ZTF0DxQ went through less than 1/4 Earth diameter yesterday, making it the closest known flyby that did not hit our planet,” Dunn tweeted on Monday. He shared the animation below, here again with permission.

The accelerated simulation shows the approximately orbital path of 2020 QG as it is provided at a speed of about 7.7 miles per second (12.4 kilometers per second) or about 27,600 mph.

Early observations suggest that the space rock flew over the Southern Hemisphere flat after 4 o’clock Universal Time (midnight ET) on Sunday.

The animation above shows 2020 QG flying across the Southern Ocean off Antarctica. However, the Minor Planet Center of the International Astronomical Union calculated a slightly different trajectory. The group’s view (shown at the beginning of this story) suggests that the asteroid flew hundreds of miles east of Australia across the Pacific Ocean.

Not dangerous, but definitely not welcome

As for space rocks, 2020 QG was not too dangerous.

Telescopic observations suggest that the object is between 6 feet (2 meters) and 18 feet (5.5 meters) wide – somewhere between the size of a small car and a pick-up truck with an extended cab. But even if it was at the largest end of that spectrum and made of dense iron (most asteroids are rocky), only small pieces of such an asteroid may reach the ground, according to the “Impact Earth” simulator from Purdue University and Imperial College London.

Such an asteroid would have exploded in the atmosphere, created a brilliant fireball and made an airburst equivalent to detonating a few tens of kilotons of TNT. That’s about the same as one of the atomic bombs that the US dropped on Japan in 1945. But the airburst would have happened about 2 or 3 miles above the ground, so it would not have sounded louder than heavy traffic to people on the ground.

This does not make the discovery of the asteroid much less enjoyable, though – it does not take large space rock to create a major problem.

Take, for example, the roughly 66-meter-wide (20-meter) asteroid that exploded without warning over Chelyabinsk, Russia, in February 2013. That space rock created a super-solid event, releasing an airburst equal to 500 kilotons of TNT – about 30 energy value of Hiroshima -nuclear bombs. The blast, which began about 12 miles (20 kilometers) above the Earth, triggered an explosion that shook windows in six Russian cities and injured about 1,500 people.

And in July 2019, a 427-foot (130-meter) asteroid named 2019 went OK within 45,000 miles (72,400 kilometers) of our planet, or less than 20% of the distance between Earth and the moon. Astronomers discovered that rock was less than a week before its closest approach, prompting one scientist to tell the Washington Post that the asteroid essentially ‘came out of nowhere.’

In an unlikely direct hit to a city, such a noisy space rock could kill tens of thousands of people.

NASA is actively scanning the skies for such threats, as Congress has required it to do since 2005. However, the agency is required to detect only 90% of the urban killer ‘space rocks larger than 140 meters in diameter.

In May 2019, NASA said it had found less than half of the estimated 25,000 objects of that size or larger. And of course that does not count smaller rocks like the Chelyabinsk and OK OK asteroids.

Objects coming from the direction of the sun are meanwhile – like 2020 QG – notoriously difficult to spot.

“There is not much that can be done to detect incoming asteroids from the direction of the sun downwards, because asteroids are detected with only optical telescopes (like ZTF), and we can only look for them in the night sky. , “said Chodas. “The idea is that we discover them on one of their previous passages through our planet, and then make predictions years and decades in advance to see if they have any possibility of impact.”

NASA has a plan to address these holes in its asteroid hunting program. The agency is in the early stages of developing a space telescope that can detect asteroids and comets from the direction of the sun. NASA’s 2020 budget has allocated nearly $ 36 million for that telescope, called the Near-Earth Object Surveillance Mission. If funding continues, it could start as early as 2025.

This story has been updated with new information.