Tracking the Chelyabinsk meteor dust plume
On February 15, 2013, a large meteor made news around the world with its brief but dramatic appearance in the skies over the Russian city of Chelyabinsk. Observations from the NASA-NOAA Suomi National Polar-Orbiting Partnership satellite tracked the meteor’s dust plume in the upper atmosphere as it took just four days to circle back to skies over Chelyabinsk. In the days, weeks, and months that followed, satellite observations of dust from the Chelyabinsk meteor – plus computer models of upper atmospheric wind currents – helped scientists predict the evolution of the dust plume as it formed a ring of dust in the upper atmosphere, over northern latitudes.
The post-dawn sky over the Russian town of Chelyabinsk on February 15 was lit by what seemed like a momentary second sun. An enormous fireball streaked across the sky, brightening as it culminated in a brilliant flash that was captured by many car dashboard cameras. Not long after, loud sonic booms from the explosion shattered glass windows, even damaging some buildings. There was widespread panic and confusion; some old enough to remember the cold war even assumed it was a nuclear attack.
NASA atmospheric physicist Nick Gorkavyi missed that once-in-a-lifetime experience, which amazed and terrified the people of his hometown. But from his office at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, he and his colleagues seized an unprecedented opportunity to track the aftermath of the meteor’s fall to earth, by following its large dust plume in the upper atmosphere using observations from the NASA-NOAA Suomi National Polar-Orbiting Partnership satellite. Their findings were recently accepted for publication in the journal Geophysical Research Letters.
Before its demise in the Earth’s atmosphere, this large meteor, also known as a bolide, was believed to measure 59 feet across and weigh 11,000 metric tons. Plunging through the atmosphere at about 41,000 miles per hour, the meteor powerfully compressed air in its way, causing the pressurized air to heat up, which in turn heated the meteor. This process escalated until, at 14.5 miles above Chelyabinsk, the meteor exploded.
While some chunks of the disintegrated space rock fell to the ground, hundreds of tons of the meteor was reduced to dust during its fiery entry into the atmosphere. Gorkavyi said in a press release:
We wanted to know if our satellite could detect the meteor dust. 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.
About 3.5 hours after the explosion, the Suomi satellite made its first observations of the dust plume at an altitude of 25 miles, rapidly moving east at 190 miles per hour. A day later, the satellite observed the eastward-moving plume carried by the stratospheric jet stream — air currents in the upper atmosphere — over the Aleutian islands that lie between the Alaskan Peninsula and Russia’s Kamchatka Peninsula. By then, heavier dust particles were slowing down and descending to lower altitudes, while lighter dust continued to stay aloft at the wind speeds of their respective altitudes. Four days after the explosion, the lighter dust particles riding faster air currents had made a complete circle around the upper northern hemisphere, returning to where it all started, over Chelyabinsk.
Gorkavyi and his colleagues continued to follow the plume as it dissipated in a belt in the upper altitudes of the atmosphere. Three months later, the dust belt was still detectable by the Suomi satellite.
Using initial satellite measurements of the meteor dust and atmospheric models, Gorkavyi and his collaborators created simulations of the dust plume’s journey through the upper atmosphere of the northern hemisphere. Their predictions were confirmed via subsequent satellite observations of the meteor dust dispersal. Paul Newman, chief scientist for Goddard’s Atmospheric Science Lab, said in the same press release,
Thirty years ago, we could only state that the plume was embedded in the stratospheric jet stream. Today, our models allow us to precisely trace [the dust from] the bolide and understand its evolution as it moves around the globe.
The simulated meteor dust plume dispersal, as shown in this video, accurately predicted the actual dust plume motion that was recorded by satellite observations.
Each day, the Earth is bombarded by tons of particles in its path as it orbits the sun. Much of it ends up suspended in the upper atmosphere. Yet, when compared to lower layers of the atmosphere that have more suspended particles from volcanoes and other natural sources, the upper atmosphere seems relatively clean, even with the recent addition of particles from the Chelyabinsk meteor. Suomi satellite observations of the dust plume have demonstrated that fine particles in the atmosphere can be measured quite precisely, opening new opportunities for studying the physics of the upper atmosphere, monitoring meteor breakups in the atmosphere, and for learning how these extraterrestial particles affect cloud formation in the upper and outmost reaches of the atmosphere. Said Gorkavyi, in the press release,
… 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. 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.
Bottom line: When a large meteor exploded over the town of Chelyabinsk, Russia, on February 15, 2013, it presented NASA atmospheric physicists with a unique opportunity to track the large dust plume that resulted from the explosion and disintegration of the meteor. Dust particles were observed for several months by the NASA-NOAA Suomi National Polar-Orbiting Partnership satellite. Initial observations following the explosion and models of the atmospheric air currents were able to successfully predict the evolution of the dust plume as it settled into a global ring of dust in the upper atmosphere, suspended over the northern hemisphere. This analysis opens new doors in monitoring particles in space that enter and get caught in the upper atmosphere, and how it affects cloud formation at high atmospheric altitudes.