TORONTO – The meteor that streaked across the Russian sky on Feb. 15, 2013, left a plume that circled our globe, a satellite has discovered.
The fireball, or bolide, exploded over Chelyabinsk, Russia, just after dawn. The shockwave that the meteor caused as it pushed the air ahead of it shook the town, damaging buildings and injuring people as windows exploded.
Scientists estimate that the meteor was 18 metres across, and weighed approximately 11,000 metric tons. It hit Earth’s atmosphere at a mind-blowing 18.6 km/s and exploded 23.3 km above the town, releasing more than 30 times the energy from the Hiroshima bomb.
Although some pieces of the meteor fell to the ground, it also left hundreds of tonnes of material in the stratosphere.
A NASA satellite made unprecedented measurements of the material and charted its progress in the days that followed.
“We wanted to know if our satellite could detect the meteor dust,” said Nick Gorkavyi, of NASA’s Goddard Space Flight Center in Greenbelt, Md., who led the study, which has been accepted for publication in the journal Geophysical Research Letters. “Indeed, we saw the formation of a new dust belt in Earth’s stratosphere, and achieved the first space-based observation of the long-term evolution of a bolide plume.”
Although Gorkavyi is from Chelyabinsk, he was in Greenbelt, Md.,at the time.
About three-and-a-half hours after the explosion, the Ozone Mapping Profiling Suite Instrument’s Limb Profiler on the NASA-NOAA Suomi National Polar-orbiting satellite detected the plume about 40 km in the atmosphere, travelling more than 300 km/h.
Four days later, the higher level of the plume had circled the Northern Hemisphere returning over Chelyabinsk.
But the trip wasn’t over yet: four months later the plume was still around the planet.
Researchers continue to analyze the findings in the hope of better understanding how bolide events may influence clouds in the upper atmosphere.