An apparent meteor passing through the atmosphere just east of Boston caused a loud boom heard over multiple areas of Massachusetts around 2 p.m. on Saturday, according to Ken Mahan, lead meteorologist for the Boston Globe.<\/p>\n
\u201cIt\u2019s a bolide meteor, which is essentially a fireball,\u201d Mahan said. \u201cThese are large and often spark a sonic boom when passing through the atmosphere with speeds faster than the sound barrier and air compressing ahead of the meteor as it races through, generating a massive pressure wave.\u201d <\/p>\n
\u201cThe average size bolide meteor sits at 1-2 meters,\u201d he added. \u201cNASA will ultimately estimate the size of this meteor in the coming days.\u201d<\/p>\n
John Ebel, a senior research scientist at Weston Observatory in Boston College, said in a phone interview Saturday that if not for heavy cloud cover, a fireball might have been visible over the Massachusetts coast.<\/p>\n
\u201cIt must have gotten pretty far into the atmosphere,\u201d he said, adding that sound waves from meteors entering the upper atmosphere usually dissipate by the time they reach the ground.<\/p>\n
Ebel said an earthquake couldn\u2019t have caused the sound because atmospheric pressure waves, which come from the sky, were much stronger than seismic signals he detected on the ground.<\/p>\n
\u201cMy automated system for detecting earthquakes didn\u2019t trigger,\u201d he said.<\/p>\n
Mahan said small meteors enter the atmosphere all the time, but typically don\u2019t make a sound as loud as the one heard Saturday afternoon. <\/p>\n
The apparent meteor \u201chad to be much larger and traveling faster than normal meteors to make a sound this loud,\u201d he said.<\/p>\n
James Ryan, a professor emeritus of physics and a researcher at the Space Science Center at the University of New Hampshire, said satellite imagery of the shockwave is \u201cconsistent with a good-sized meteor.\u201d<\/p>\n
\u201cMeteors cast a very wide range of sonic booms,\u201d he said. <\/p>\n