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In January, there were sightings of a fireball in the sky over Southeast Michigan. The following day, the United States Geological Survey confirmed it was a meteoroid which had exploded in the atmosphere. At the time, the loud "boom" it caused was reported to register at 2.0 on the Richter scale, but for the USGS and NASA, it didn't seem like that big of a deal. Now, it turns out this was all captured by a large number of sensors including cameras, seismometers, and infrared microphones providing scientists with a lot more information than they would normally get from this sort of event. Jeroen Ritsema is a seismologist and Professor of Earth and Environmental Sciences at the University of Michigan. He joined Stateside's Lester Graham to discuss what this data revealed about this particular meteoroid. According to Ritsema, this concentration of sensors provided scientists with three key observations: ground motion, recording of sound, and satellite images of visible light. The seismic activity that was recorded was caused simply by the sound of the meteoroid explosion. "The sound of the explosion propagates through the atmosphere and it perturbs the ground a little bit, and that's enough for us to see on the seismometers that are buried within the ground," Ritsema said. Listen above to hear Ritsema discuss how scientists are making sense of all this data collected and how useful it will be. This post was written by Stateside production assistant Sophie Sherry. |
原文地址:http://www.tingroom.com/lesson/mxgxwgb/520740.html |