A streak, a boom, and now meteor debris?
Ellen Huet
Updated 4:20 p.m., Thursday, October 18, 2012
(10-18) 15:07 PDT SAN FRANCISCO -- A bright flash across the sky and a shaking boom awed Bay Area onlookers Wednesday evening, and one scientist says souvenirs of the phenomenon might be strewn in the hills around Martinez.
A meteor, perhaps the size of a small car when it hit the Earth's atmosphere, put on a spectacular lightshow at 7:45 p.m. that was visible throughout the Bay Area and elsewhere in Northern and Central California.
The accompanying noise was the meteor's sonic boom as it traveled faster than the speed of sound, said Jonathan Braidman, an astronomy instructor at Oakland's Chabot Space and Science Center.
"These meteors travel 25,000 miles per hour or more," Braidman said. "When they hit the atmosphere they slow down considerably and break up into tiny, glittering fragments."
And those meteorite fragments, Braidman said, could well be scattered throughout the East Bay hills near Martinez, ready to be picked up by anyone willing to put in the effort to track them down.
It won't be easy. Braidman said the pieces could be anywhere over hundreds of square miles, with the Martinez hills estimate based mostly on eyewitness accounts and a northward trajectory of the meteor.
Meteors burn through the Earth's atmosphere "all the time," Braidman said. But most of them shine in obscurity, streaking over the ocean or land where no one lives.
"For it to flash across a populated area like the Bay Area, it's pretty rare," he said. "What's special now is we have so many people collecting data, taking pictures, that it's possible to see it streaking over the sky and maybe find out where it landed. Before, we were never able to do that."
Exclamations of meteoric shock and surprise were immediately posted on Twitter and other social media from locations as far south as San Luis Obispo County. Some people who spotted the meteor had no idea what they were looking at, but they knew it was something unusual.
"It was a big, huge fireball," said Tyler Clark, 19, who spotted it near his home in Manteca. "It was huge - bigger than the moon. All I saw was tons of flames coming off of it, and the next thing I knew, it vanished."
Clark said the meteor was visible for several seconds and burned mostly white, with red and yellow flame-like tinges.
"I was scared, not gonna lie - I thought it hit us," he said. "I was waiting for something to happen. I told my friends, 'Better start praying.' "
Clark can rest easy. Meteorite fragments that reach land are usually small enough to fit in the palm of a hand, Braidman said.
Their value depends on whether they're made of metal or of a stonier material.
Bob Moreno was fortunate enough to have a good camera on hand. He was snapping photos of his daughter's high school soccer game at Cardinal Newman High School in Santa Rosa when he spotted a small, bright spot slowly moving across the sky.
"The first thing I thought was, 'Wow. Is that a plane crashing or something?' " said Moreno, 54. "And then I stopped thinking and thought, 'I need to take a picture of it.' "
Moreno said the streak grew brighter and he realized it was a meteor. It covered a 90-degree arc of the sky for several seconds before disappearing, he said.
"It was like a brilliant light fist with things trailing behind it - reddish embers," Moreno said. "The tail got a little longer, a little longer, then the head of it - the fist part - crumbled from underneath. It turned into four or five distinct pieces, each with a tail, then those broke up. It was like a firework, at the end, when the embers just die."
Anyone who finds something they think might be part of a meteorite can bring it to the Chabot center or to one of a number of universities to be tested.
Braidman said the meteor was unrelated to the upcoming Orionid meteor shower, which will peak this weekend as the Earth passes through the tail of Halley's comet.
The shooting stars that people spot during meteor showers are much smaller pieces of comet-tail dust burning up in the atmosphere, not large meteors like this one, Braidman said.
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