Researchers Obtain Crucial Data from Meteoroid Impact

This photograph of the meteor streaking through the sky above Chelyabinsk, Russia, on February 15, 2013, was taken by a local, M. Ahmetvaleev.

Washington — A team of NASA and international scientists for the first time have gathered a detailed understanding of the effects on Earth from a small asteroid impact.

The unprecedented data obtained as the result of the airburst of a meteoroid over the Russian city of Chelyabinsk on February 15, 2013, has revolutionized scientists’ understanding of this natural phenomenon, NASA said in a November 6 press release.

The Chelyabinsk incident was well observed by citizen cameras and other assets. This provided a unique opportunity for researchers to calibrate the event, with implications for the study of near-Earth objects and developing hazard-mitigation strategies for planetary defense. Scientists from nine countries have now established a new benchmark for future asteroid impact modeling.

“Our goal was to understand all circumstances that resulted in the shock wave,” said meteor expert Peter Jenniskens, co–lead author of a report published in the journal Science. Jenniskens, a meteor astronomer at NASA’s Ames Research Center in California and the SETI Institute, participated in a field study led by Olga Popova of the Institute for Dynamics of Geospheres of the Russian Academy of Sciences in Moscow in the weeks following the event.

“It was important that we followed up with the many citizens who had firsthand accounts of the event and recorded incredible video while the experience was still fresh in their minds,” Popova said.

By calibrating the video images using the position of the stars in the sky, Jenniskens and Popova calculated the impact speed of the meteor at 19 kilometers per second. As the meteor penetrated through the atmosphere, it fragmented into pieces, peaking at 30 kilometers above the surface. At that point the light of the meteor appeared brighter than the sun, even for people 100 kilometers away.

As a result of the extreme heat, many pieces of the debris vaporized before falling out of the orange, glowing debris cloud. Scientists believe that between 4,000 and 6,000 kilograms of meteorites fell to the ground. This included one fragment weighing approximately 650 kilograms recovered from Lake Chebarkul on October 16 by professional divers guided by Ural Federal University researchers.

NASA researchers participating in the 59-member consortium study suspect that the abundance of shock fractures in the rock contributed to its break-up in the upper atmosphere. Meteorites made available by Chelyabinsk State University researchers were analyzed to learn about the origin of the shock veins and their physical properties.

The impact that created the shock veins may have occurred as long ago as 4.4 billion years. This would have been 115 million years after the formation of the solar system, according to the research team, who found that the meteorites had experienced a significant impact event at that time.

“Events that long ago affected how the Chelyabinsk meteoroid broke up in the atmosphere, influencing the damaging shockwave,” Jenniskens said.

Research is being conducted to better understand the origin and nature of near-Earth objects. These essential studies are needed to inform the approach to preparing for the potential discovery and deflection of an object on a collision course with the Earth.

NASA’s recently announced asteroid initiative will be the first mission to capture and relocate an asteroid.

The study of asteroids and comets allows scientists to learn more about the origins of the solar system, the source of water on the Earth, and even the origin of organic molecules that lead to the development of life, NASA said.