From Greenbelt, Md., however, NASA's Gorkavyi and colleagues witnessed a never-before-seen view of the atmospheric aftermath of the explosion.
Model and satellite data show that four days after the bolide explosion, the faster, higher portion of the plume (red) had snaked its way entirely around the northern hemisphere and back to Chelyabinsk, Russia.
Image Credit: NASA's Goddard Space Flight Center Scientific Visualization
Shortly after dawn on Feb. 15, 2013, the meteor, or bolide, measuring 59 feet (18 meters) across and weighing 11,000 metric tons, screamed into Earth's atmosphere at 41,600 mph (18.6 kilometers per second). Burning from the friction with Earth's thin air, the space rock exploded 14.5 miles (23.3 kilometers) above Chelyabinsk.
The explosion released more than 30 times the energy from the atom bomb that destroyed Hiroshima. For comparison, the ground-impacting meteor that triggered mass extinctions, including the dinosaurs, measured about 6 miles (10 kilometers) across and released about 1 billion times the energy of the atom bomb.
ome of the surviving pieces of the Chelyabinsk bolide fell to the ground. But the explosion also deposited hundreds of tons of dust up in the stratosphere, allowing a NASA satellite to make unprecedented measurements of how the material formed a thin but cohesive and persistent stratospheric dust belt.
"We wanted to know if our satellite could detect the meteor dust," said 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."
Gorkavyi and colleagues combined a series of satellite measurements with atmospheric models to simulate how the plume from the bolide explosion evolved as the stratospheric jet stream carried it around the Northern Hemisphere.
About 3.5 hours after the initial explosion, the Ozone Mapping Profiling Suite instrument’s Limb Profiler on the NASA-NOAA Suomi National Polar-orbiting Partnership satellite detected the plume high in the atmosphere at an altitude of about 25 miles (40 kilometers), quickly moving east at about 190 mph (more than 300 kph).
The day after the explosion, the satellite detected the plume continuing its eastward flow in the jet and reaching the Aleutian Islands. Larger, heavier particles began to lose altitude and speed, while their smaller, lighter counterparts stayed aloft and retained speed – consistent with wind speed variations at the different altitudes.
By Feb. 19, four days after the explosion, the faster, higher portion of the plume had snaked its way entirely around the Northern Hemisphere and back to Chelyabinsk. But the plume’s evolution continued: At least three months later, a detectable belt of bolide dust persisted around the planet.
The scientists' model simulations, based on the initial Suomi NPP observations and knowledge about stratospheric circulation, confirmed the observed evolution of the plume, showing agreement in location and vertical structure.
"Thirty years ago, we could only state that the plume was embedded in the stratospheric jet stream," said Paul Newman, chief scientist for Goddard's Atmospheric Science Lab. "Today, our models allow us to precisely trace the bolide and understand its evolution as it moves around the globe."
The full implications of the study remain to be seen. Every day, about 30 metric tons of small material from space encounters Earth and is suspended high in the atmosphere. Even with the addition of the Chelyabinsk debris, the environment there remains relatively clean. Particles are small and sparse, in contrast to a stratospheric layer just below where abundant natural aerosols from volcanoes and other sources collect.
Still, with satellite technology now capable of more precisely measuring tiny atmospheric particles, scientists can embark on new studies in high-altitude atmospheric physics. How common are previously unobservable bolide events? How might this debris influence stratospheric and mesospheric clouds?
Scientists previously knew that debris from an exploded bolide could make it high into the atmosphere. In 2004, scientists on the ground in Antarctica made a single lidar observation of the plume from a 1,000-ton bolide.
"But now 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, 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."Kathryn Hansen
Maria-Jose, Vinas Garcia | EurekAlert!
Scientists discover Earth's youngest banded iron formation in western China
12.07.2018 | University of Alberta
Drones survey African wildlife
11.07.2018 | Schweizerischer Nationalfonds SNF
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
16.07.2018 | Physics and Astronomy
16.07.2018 | Transportation and Logistics
16.07.2018 | Agricultural and Forestry Science