Trove of data from Russian 'dash-cam' meteorite

November 27, 2013 by Simon Redfern, The Conversation
Is it a bird, is it a plane? Credit: alexeya

The asteroid impact that burst over Chelyabinsk, Russia, on the morning of February 15 has provided a huge collection of new data that scientists have been analysing since. This week, three papers, two in Nature and one in Science, describe new aspects of the meteorite's airburst, building the most-detailed forensic picture of the events of that morning.

First reports of the Chelyabinsk airburst came from a plethora of dash-cams that caught the event. For the first time, a meteorite impact was recorded widely on camera, a consequence of technological advance and (presumably) increasingly litigious or bad Russian drivers. Alongside the dash-cam recordings, the fireball and the transient shadow that it cast was recorded across the region by fixed CCTV cameras. And looking back at Earth from space, the trajectory of the fireball was observed in satellite imagery.

The brightness of the fireball has provided an estimate of the energy of the airburst, equivalent to an explosion of more than 500 kilotons of TNT, many times greater than the Hiroshima atomic bomb. Similar estimates of the size of the explosion were obtained earlier this year from the array of infrasound detectors operated by the Comprehensive Nuclear Test Ban Treaty Organization, which maintains an array of nuclear bomb monitoring equipment.

The new papers exploit an even wider array of data. Much of the information is, effectively, a superb example of crowdsourced science: damage reports, surveys of damage, injury reports, camera recordings and other data have provided an unprecedented set of measurements of the event, as reported in Science by Olga Popova and colleagues.

This video is not supported by your browser at this time.

Alongside the data from Earth is information from astronomy, planetary science, geophysics, meteoritics and cosmology. The meteorite that fell to Earth has now been classified as an LL chondrite. It formed early in the history of the Solar System, as asteroids and eventually planets condensed from the nebula.

Fragments of the meteorite recovered from near Chelyabinsk, including an enormous rock dredged from the bottom of Lake Chebarkul, have revealed its early history. We have all this even though less than one thousandth of the asteroid has been retrieved, and more than three quarters is estimated to have evaporated.

Measurements of the radioactive decay products from traces of uranium in the meteorite minerals show that it must have itself suffered a harsh collision during the maelstrom in which asteroids condensed, which occurred at around 115m years after the birth of the Solar System. Its existence as a discrete asteroid ended almost four and a half billion years later when it struck Russia.

The eyewitness reports of the airburst, as well as the damage it caused, give an idea of the sorts of effects caused by such "near miss" events. Entering the atmosphere almost 100km above the surface, at speeds of around 20km/second, the 20-metre wide asteroid set up a shockwave at 90 km altitude. By 83 km it had started to fall apart. By the time it got to around 35 km above Russia it was shining as a bright shooting star, emitting light that burnt the retinas of any watching it, and sending out a shockwave sideways from its path that blew some folk off their feet.

As the video makes it clear, the shockwave broke phone networks, upset the electric grid, and interrupted the gas supply in some districts of Emanzhelinka as the valves closed in response to the vibration. No bones were broken, but some residents were hurt by flying debris and glass, while others suffered concussion.

Similar descriptions of the trajectory, determined from video data, are reported by in the first Nature paper. Risk estimates for asteroid fireball damage have, up to now, been based on data from airburst tests. In the second Nature paper, researchers compare damage caused by the Chelyabinsk airburst with previous models for asteroid damage showing that the risks have been underestimated. The latest data increase the potential danger of impacts from asteroids tens of metres across.

These results demonstrate the forensic value of the asteroid that fell to Earth in February this year, both for assessing how such bodies come into existence, and interact with our planetary home, but also how we might assess the risk of such events into the future.

Explore further: Russia asteroid impact: ESA update and assessment

Related Stories

Russia asteroid impact: ESA update and assessment

February 19, 2013

The first firm details of the 15 February asteroid impact in Russia, the largest in more than a century, are becoming clear. ESA is carefully assessing the information as crucial input for developing the Agency's asteroid-hunting ...

Big meteorite chunk found in Russia's Ural Mountains

February 27, 2013

Scientists and meteorites hunters have been on a quest to find bits of rock from the asteroid exploded over the city of Chelyabinsk in Russia on February 15. More than 100 fragments have been found so far that appear to be ...

Insight into space collisions from Chelyabinsk fireball

October 11, 2013

Scientists from the Czech Republic, Finland, and the Russian Federation are presenting today new findings on meteorites recovered after the Chelyabinsk fireball that exploded over Russia on February 15, 2013. The report was ...

First study results of Russian Chelyabinsk meteor published

November 6, 2013

The meteor that exploded over Chelyabinsk, Russia in February 2013 was "a wake-up call," according to a University of California, Davis scientist who participated in analyzing the event. The work is published November 7, ...

Recommended for you

NASA's space-station resupply missions to relaunch

November 29, 2015

NASA's commercial space program returns to flight this week as one of its private cargo haulers, Orbital ATK, is to launch its first supply shipment to the International Space Station in more than 13 months.

The hottest white dwarf in the Galaxy

November 25, 2015

Astronomers at the Universities of Tübingen and Potsdam have identified the hottest white dwarf ever discovered in our Galaxy. With a temperature of 250,000 degrees Celsius, this dying star at the outskirts of the Milky ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.