Bay City News Service—A large meteor streaked across the night sky Wednesday evening and was seen and heard throughout the Bay Area.
Sky observers took to social media to report that they had seen a bright fireball with hues of red and orange break up overhead shortly before 8 p.m., accompanied by a loud boom. The sound was so loud, some residents reported it shook their homes, making them think it may be an earthquake.
Jonathan Braidman, astronomy instructor at Oakland's Chabot Space and Science Center, said the meteor likely hit the Earth around the Martinez Hills and was roughly the size of a car when it broke up over the Bay Area. Braidman said that hikers may be able to find small pieces of the meteor, called meteorites once they land on Earth, in the hills north of Martinez.
However, the American Meteor Society reports that it appears the fireball approached form over the ocean and that most likely any fragments are at the bottom of the sea.
Meteors are hunks of rock and metal that have broken off from asteroids and fallen from space, breaking up as they enter Earth's atmosphere. Braidman said that meteors hit the upper layer of Earth's atmosphere traveling at 25,000 mph or more. Then the atmosphere slows them down and breaks them up so that when they hit the ground, they are traveling at a speed of between 200 and 400 mph.
Wednesday night's meteor appeared for about four or five seconds and was traveling fairly slowly compared to some other meteors, indicating it was probably fairly large. But the noise that residents heard was a sonic boom, caused by the falling object traveling faster than the speed of sound, so it was probably moving at over 1,000 mph, Braidman said.
Braidman said that the meteor is not related to the Orionid meteor shower expected to peak Saturday night and early Sunday morning.
Braidman said the "shooting stars" that stargazers will see this weekend are in fact small pieces of comet. The Orionid phenomenon is predictable because it occurs when Earth passes through the trail of Halley's Comet, but Wednesday's meteor sighting was unexpected, despite that as much as 15,000 tons of material falls from space each year.
"Even though this kind of thing happens often, it's pretty rare for people to see it," Braidman said.
Wednesday night's meteor was visible throughout the Bay Area, with sightings reported in Oakland, Santa Cruz, San Jose, Oakland, Pacifica, Daly City, Sausalito and Davis among other communities.
For more about Wednesday night's meteor, visit the American Meteor Society's website, http://www.amsmeteors.org/2012/10/massive-fireball-over-california-coast-october-17th-2012/
The Chabot Space and Science Center offers free public star viewings on Friday and Saturday nights starting at 7:30 p.m. In addition to the Orionid shower, viewers this weekend can observe Jupiter, the Moon and nebulae. The observatory is at 10000 Skyline Blvd. in the Oakland Hills.
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