Vermont Meteor's Violent Explosion Causes Earth Tremors Detected by NASA On 3/9/21 at 6:19 AM EST The meteor that exploded over the state of Vermont on the evening of March 7 was detected by ground-based seismometers, NASA has said. The space rock violently broke apart in Earth's atmosphere around 33 miles high, causing a shockwave that could be measured and heard by instruments. NASA revised its speed estimate on March 8 and said the meteor was traveling at around 42,000 miles per hour. This is more than 20 times faster than a rifle bullet, or 55 times faster than the speed of sound. The speed estimate was based on more than 100 eyewitness reports.