NASA Meteor Watch page has some more data and have revised the numbers for the best match. Here’s what we know now:
Nearly 200 eyewitnesses have filed accounts on the American Meteor Society website of a bright fireball occurring over the states of Virginia and Maryland last evening (July 28) at 9:57 PM Eastern Daylight Time. Analysis of these reports, combined with constraints from a NASA all sky camera at Allegheny Observatory and EarthCams on the Washington Monument and in Baltimore Harbor, gives first visibility of the fireball at an altitude of 52 miles above Stephens City, Virginia. The meteor moved to the northwest at 46,000 miles per hour, disintegrating 32 miles above the town of Frostburg in Maryland. At its brightest, the fireball was about 2 times brighter than the Full Moon.
The disintegration of the object unleashed an energy equal to 9 tons of TNT, recorded by an infrasound station in the area. From this, we can compute that the object – likely a small piece of an asteroid – was about 18 inches in diameter and weighed approximately 200 pounds.
We thank the American Meteor Society for providing the eyewitness accounts.
