Debris From Russian Meteor Explosion Wrapped the Globe, Lasted for Months
When a meteor weighing some 11,000 metric tons exploded over Russia earlier this year, much of the remaining debris fell to the ground -- but not all. Ultimately, some 100 tons of dust from the meteor, or bolide, became locked in the atmosphere, offering NASA officials an unprecedented opportunity to observe as this material went on to create a thin but cohesive dust belt in the stratosphere.
"We wanted to know if our satellite could detect the meteor dust," said atmospheric scientist Nick Gorkavyi of NASA's Goddard Space Flight Center in Greenbelt, Md. "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."
Gorkavyi and his colleagues took notes as less than four hours after the meteor exploded, the Ozone Mapping Profiling Suite instrument's Limb Profiler on the NASA-NOAA Suomi National Polar-orbiting Partnership satellite detected a plume of debris at an altitude of about 25 miles moving east at about 190 mph.
They then watched a day later as the satellite observed the plume continuing its eastward trek, reaching the Aleutian Islands. The researchers noted that, consistent with wind speed variations at the different altitudes, heavier particles began to drop in terms of speed and altitude while their smaller counterparts skipped along above them at higher speeds.
Within four days, the higher portion of the plume had made its way all the way around the globe, arriving where it started in the city of Chelyabinsk. Three months later, the cloud was still detectable.
Ultimately, the researchers stress that, though detectable, the particles are small and sparse, posing no real environmental threat, especially in light of the tens of metric tons of small space material dropped on Earth every day.
More significant, they say, are the new studies in high-altitude atmospheric physics made available now that satellite technology is capable of precisely measuring tiny atmospheric particles. Previously, scientists knew that debris from an exploded meteor could make it high into the atmosphere. However, "in the space age, with all of this technology, we can achieve a very different level of understanding of injection and evolution of meteor dust in atmosphere," Gorkavyi said.
"Of course," he admits, " the Chelyabinsk bolide is much smaller than the 'dinosaurs killer,' and this is good: We have the unique opportunity to safely study a potentially very dangerous type of event."