WEBVTT FILE

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(music)

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It's early morning

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on February 15th, 2013.

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A meteor weighing 10,000

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metric tons is about to explode nearly 23 km

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above Chelyabinsk.

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Shortly after local sunrise:

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a blinding sight for the stunned spectators on the ground,

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(sound of explosion)

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a massive explosion equivalent to 440 kilotons of TNT,

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hundreds of tons of debris released, and quickly moved up into the atmosphere.

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The highly sensitive

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OMPS instrument on board the Suomi/NPP satellite made its first observation

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of the plume nearly three and a half hours later, an entire

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1.100km east of the explosion and already at

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40km altitude well. into the Earth's stratosphere!

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A surprising observation since the stratosphere usually acts as a

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bumper that caps aerosols trying to rise up from the lower atmosphere.

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By inserting a column of data

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from the first plume observation into to two NASA models,

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scientists were able to project the plume's trajectory.

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The models showed that the plume had higher altitudes, shown in red, would

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move ahead of the lower layer, shown in yellow.

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The reason would be the difference in wind velocity at the lower and

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higher altitudes. Also

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illustrated here is how accurately the satellite observations coincided

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with the projected path of the plume.

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(music)

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When OMPS made its second observation back at Chelyabinsk,

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nearly 5 hours after the bolide, there was still evidence of

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the plume at a lower 30km altitude.

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On February 16, one day after the bolide, the OMPS instrument

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detected the far end of the plume even further, at 1,700

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to 4,300 km eastward from the explosion.

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By February 19th,

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four days after the explosion, the satellite observation showed that

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the meteor debris had circumnavigated the entire globe and returned to

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Chelyabinsk, forming a complete global belt.

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The clean shape of the belt was another

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surprising prediction, considering that Northern hemisphere winds during the winter

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are usually rather inconsistent in direction.

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A further look into the model simulation showed that evidence of the plume

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persist for a long time, which also coincided with the satellite

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observations.

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We have now seen how accurately the models were able to project the plume's

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trajectory. This is critical since the same models

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are used to study climate and ozone depletion. The

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unprecedented sensitivity of the OMPS instrument and its ability to see

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vertical profile the atmosphere help scientists track

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and study the meteor plume for months, revealing a much

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better picture of what the aftermath on the atmosphere could be

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from potential future, and even bigger events.

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(beeping)

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(beeping)

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(beeping)

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