When a meteor weighing 11,000 metric tons exploded about 15 miles over Chelyabinsk, Russia, on Feb. 15, 2013, city native Nick Gorkavyi, an atmospheric physicist for NASA’s Goddard Space Flight Center, was half a world away in Greenbelt, Md. However, Gorkavyi has been able to serve as an important witness to what happened in the aftermath of the massive impact by tracking the evolution of the enormous dust plume that the explosion created. The results of the study by Gorkavyi and his colleagues have been accepted for publication in the journal Geophysical Research Letters.
The large Russian meteor, which measured 59 feet (18 meters) across, crashed into Earth’s atmosphere at more than 41,000 miles per hour. It rained down boulders as large as buses on Gorkavyi’s hometown of Chelyabinsk and injured more than 1,000 people. The explosion released energy more than 30 times that of the atom bomb that leveled Hiroshima at the end of World War II, NASA officials stated in a news release. That’s a lot–but compared to the six-mile-across meteor that released more than one billion times the energy as the atom bomb and triggered the worldwide mass extinction of dinosaurs, it was a rather modest-sized explosion incapable of large-scale devastation.
In addition to the downpour of rock that fell on Chelyabinsk, the explosion also sent hundreds of tons of dust into the stratosphere. The stratosphere, where the ozone is located, is the second major atmospheric level above the troposphere and ranges in altitude from about eight to 30 miles. It is also accessible to a NASA satellite, which Gorkavyi and his colleagues used to make ground-breaking measurements of how the giant plume of dust created by the meteor’s explosion formed a thin and persistent “stratospheric dust belt.”
In a statement, Gorkavyi said his team was interested in whether NASA’s Suomi National Polar-orbiting Partnership (NPP) satellite could track the Chelyabinsk meteor’s dust cloud. They combined a series a satellite measurements with atmospheric models to simulate how the dust plume developed and changed as the stratospheric jet stream carried it around the Northern Hemisphere. In the first space-based observation of the evolution of a meteor’s dust plume, the researchers saw what Gorkavyi described as “the formation of a new dust belt in Earth’s stratosphere.”
The team found that about three-and-a-half hours after the initial meteoric impact, the Suomi NPP satellite’s Ozone Mapping Profiling Suite instrument’s Limb Profiler detected the dust plume in the atmosphere at an altitude of about 25 miles (40 kilometers). The dust cloud rapidly moved eastward at a rate of about 190 miles per hour (over 300 kilometers per hour), NASA said. Four days later, the fastest, highest part of the plume had created a ring all the way around the Northern Hemisphere and back to Chelyabinsk. After three months, the belt of meteoric dust remained around the planet.
Commenting on recent scientific advances, Paul Newman, chief scientist for Goddard’s Atmospheric Science Lab, said that thirty years ago it would have been possible only to state that the dust plume was caught in the stratospheric jet stream. Today’s models, he said, now allow scientists to trace precisely the dust from meteor impacts and learn about its evolution as it travels around the planet.
NASA says that while the full implications of the study remain to be realized, current space-age technology, which can now measure the tiniest of atmospheric particles, will pave the way for new research in high-altitude atmospheric physics.