Back in February, the internet erupted when videos of a massive explosion over a Russian city hit YouTube in the form of dash cam videos. In tomorrow’s issue of ScienceXpress, those videos act as a primary source of evidence for scientists looking to better understand what is now known as the Chelyabinsk meteor.
Over the last few months, a team of researchers, led by Olga Popova of the Russian Academy of Sciences and including folks from NASA, tried to reconstruct the characteristics of the meteor and its trajectory. Now we do know that amateur videos actually helped science in the immediate aftermath of the event. But by examining even more dash cash videos, witness reports, and meteorite fragments, Popova and nearly 60 of her colleagues were able to obtain the clearest illustration yet of the meteor since it made its very loud, bright, and brash entrance.
Here's what they found: When the meteor first entered Earth’s atmosphere, it had a mass of 1.3 x 107 kilograms. The rock whizzed through at a speed of 19-kilometers per second, or upwards of 40,000 mph. The process of falling to Earth evaporated 76 percent of the thing; the rest was reduced to dust. Whatever shards survived only accounted for around 0.05 percent of the of the initial mass of the object. The largest, discovered last month in a Russian lake, was 650 kilograms.
On the ground, some locals found themselves with meteor-related injuries. At its brightest, the meteor momentarily flashed brighter than the sun, causing mild to severe sunburns as well as some short-term retinal damage. Some people were knocked to the ground by the pure magnitude of its shock wave, which could account for the reports of concussions and bruises.
Physical structures also felt the wrath of the Chelyabinsk meteor. In the city itself, researchers found that 44 percent of apartment buildings sustained some form of damaged glass as a result of the meteor’s shock wave. Additionally, some utilities and cell phone service was disrupted in the space object’s path.
Ultimately, experimentation in the lab demonstrated that the object was an “ordinary chondrite” formed around 4,452 million years ago. Chondrites are the most common category of meteor to make its way to the Earth, so this was not a surprise.
But Chelyabinsk wasn’t the first time a massive astronomical explosion played out over Russia. In June 1908, the area known today as Krasnoyarsk Kai was ground zero of the Tunguska event. The gargantuan air burst trampled 80 million trees (pdf) and is considered untouched in its magnitude throughout recorded history.
Chelyablink’s explosion still pales in comparison with that of Tunguska, but the advent of modern technologies have made the more recent explosion just as significant, if not more, in terms of the opportunity it offers for science. Said Qing-Zhu Yu of the University of California, Davis, the explosion is a “unique calibration point for high energy meteorite impact events for our future studies.”
Stats and science aside, the videos are still a rad and disconcerting reminder that a little bit of apocalypse can rain down upon our measly little planet at any time.