A bright fireball streaks across the sky near the junction of Yushu in Qinghai Province and Qamdo in Tibet at 7:23 am on December 23, 2020.
It was the middle of winter, and for the region, the sun would not rise for more than an hour. The sky was still dark. But a sudden light made the heavens and the earth as bright as day, for half a minute.
For hundreds of kilometers around, many people looked up as the night sky became so bright that they even had enough time to get out their phones and record the spectacle. Soon, the videos went viral on social media.
Qiangqian county, yushu, qinghai, the strange light will illuminate the world | source network
The main witnesses came from Zaduo and Nangqian counties in Qinghai’s Yushu region, and the houses and ground in the county towns could be seen being illuminated for the daytime appearance. At the end of part of the video, the fireball can be seen breaking into pieces as it disappears.
Flight TV 6018 also saw the same bright light from the | source network at 10,000 metres
TV 6018, flying from Xi ‘an to Lhasa, was 100 kilometers southwest of Xining, and the incident was also witnessed at an altitude of 10,000 meters.
In nagqu, xizang, the first half of the fireball was captured on the | source network by the dashcam
In addition, a video recording from a dashcam in Nagqu, Xizang province, clearly shows the fireball lasting more than 30 seconds.
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The locations of the witnesses were spread out over hundreds of kilometers, according to |
There are sightings in such a large range, indicating that the luminous altitude is not low, far higher than the cruising altitude of 10,000 meters of civilian passenger aircraft, probably in the tens to hundreds of kilometers of the air.
This corresponds to the height range of meteoric ablation: small particles of meteor or meteor shower generally burn up at about 100 kilometers.
Small meteoroids measuring only centimetres or even millimetres in size do not have enough kinetic energy to turn into such dazzling light and heat. This fireball, at least a few metres in size, would have burned to the brightness of the sun.
This large, small object can continuously ablate from 100 kilometers to tens of kilometers.
Soon another vision of the morning sky proved the point.
Colorful clouds appear in the sky above qamdo, xizang province, after a fireball
As the sun rose, the east was pale but not yet sunrise, and long, flowing clouds appeared in the sky.
Clouds are usually no more than 20 kilometers high and need to wait until around sunrise to be lit up by the sun. And in the early morning appeared in the sky these elegant clouds, must appear in the tens of kilometers or higher in the sky, can be early by the sun.
In fact, they are tiny particles left over from previous pyrometeors, floating in the upper atmosphere along with the current and acting as condensation nuclei for the tiny amounts of water vapor to condense into clouds and float along with the current. The direction from east to west was consistent with the wind field in the upper atmosphere of the stratosphere at that time.
In a satellite remote sensing image, the cloud band (red) left by the fireball is seen drifting westward
A fireball that big would almost certainly end up on the ground, and there would be plenty of them.
In 2013, a 20-meter asteroid landed in Chelyabinsk, Russia. The asteroid crashed into the atmosphere and broke up in midair. Some hundreds of kilograms of meteorites have since been collected, with some finding their way into the market for collectable meteorites.
So, do we have the possibility to pick up the Qinghai pyrometeor left meteorites?
Very difficult, I’m afraid.
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The epicentre of the fireball event, as measured by seismic waves, was reported by China seismological station
The Qinghai Seismological Network later published a seismic signal matching the time of the fireball appearance, and thus deduced a central location. But this is probably not the place where the meteorite fell.
According to relevant studies of the Chelyabinsk event in 2013, the location of the “epicenter” measured by the seismic wave was consistent with the location of meteoroid bursting at high altitude, which was the result of shock wave reaching the ground and shaking, and the final landing position of the meteorite was nearly 100 kilometers away.
According to the Qinghai pyrometeor video, the meteorite should have fallen to the south of Nangqian County, and possibly even to The territory of Naqu, Xizang province. Located on the Qinghai-Tibet Plateau, the meteorites are likely to fall in inaccessible places due to the lack of oxygen and transportation.
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CNEOS detected the qinghai meteor event | JPL/Caltech
A short time later, NASA’s Center for Small Objects near The Earth (CNEOS) registered the event.
According to NASA’s calculations, the Qinghai meteor was the most powerful impact in China since records began in 1988, with an energy equivalent of nearly 10,000 tons of TNT, equivalent to a small nuclear bomb. It was also the third most powerful extraterrestrial impact in the world after chelyabinsk in 2013.
It sounds a bit scary, but from the earth’s point of view, these collisions are pretty common. Records from recent decades show that these impacts are evenly distributed in time and space, with hundreds of tons of extraterrestrial matter falling into Earth every day. Most of them are interstellar dust or meteoroids, but occasionally such asteroids a few metres in size hit earth directly.
Don’t panic, the Earth’s atmosphere is strong enough to withstand an impact of this magnitude, unless a meteorite hits you directly on the head… Such a small probability, which has only happened a few times in recorded history, is much smaller than your chances of winning the first prize in the lottery and is completely negligible.
It’s better to have fun picking up meteorites than to worry too much about them.
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