Blogarchiv
Astronomie - Update - Spektakulärer Bolide über der USA

-

NASA and the SETI Institute are asking the public to check their video security camera footage around 7:44 p.m. PDT Wednesday night, in the hope it recorded the meteor that illuminated the sky over the Bay Area and created sonic booms. That video may help researchers study how the meteor broke during descent.

The fireball was filmed by two stations of NASA's Cameras for All-sky Meteor Surveillance (CAMS) project, located in Sunnyvale and at the San Mateo College Observatory. The calculated trajectory shows that meteorites may have fallen just north of San Pablo Bay, along a band stretching east of San Rafael towards Sonoma and Napa, a mostly agricultural area.

"This was a slow moving fireball, which greatly increases the chances that a significant fraction of it and somewhat larger pieces survived," said meteor astronomer Peter Jenniskens, of the SETI Institute. A map of the fireball’s trajectory and the general area where the search would commence can be found at the CAMS website.

-

-

Preliminary trajectory calculated by Peter Jenniskens from Sunnyvale and San Mateo College Observatory CAMS video data.

-

2012, October 18 - Only one of the three regular CAMS stations caught the fireball, the NASA/CAMS Sunnyvale station (Jim Albers). For the two other sites, the fireball was just outside the field of view. Fortunately, thanks to the single-CAMS program run by Dave Sammuels), there was a single-CAMS camera setup at the San Mateo College observatory (Dean Drumheller). That one camera provides the second view for triangulation. The video is too bloomed for the regular software processing to work, but the average frames show a nice streak, which was used to combine with the early trajectory part from Sunnyvale, using AstroRecord and FIRBAL software. The preliminary trajectory is plotted in the image above. The potential fall area is over land. The asteroid entered at a speed of 14 km/s, typical but on the slow side of other meteorite falls for which orbits were determined. Good chance a relatively large fraction of this rock survived. The fall area is in the North Bay. The orbit in space is also rather typical: perihelion distance close to Earth's orbit (q = 0.987 AU) and a low-inclination orbit (about 5 degrees). Much more accurate results will follow from a comprehensive study of the video records. Now, we hope that someone recovers a meteorite on the ground...

-

Image by San Mateo College student Paola-Castillo, using her cell phone while stuck in traffic.

-

Quelle: NASA

-

Update: 22.10.2012

Meteor Chunk Found – Hit Novato Pastor's HomeThe first confirmed piece of the big meteor that exploded over the Bay Area Wednesday has been found – a 2-inch rock that bonked the home of pastor in Novato. A meteor-tracking astronomer confirmed that it's part of a wayward ancient asteroid.

Meteor Chunk Found – Hit Novato Pastor's Home

The first confirmed piece of the big meteor that exploded over the Bay Area Wednesday has been found – a 2-inch rock that bonked the home of pastor in Novato. A meteor-tracking astronomer confirmed that it's part of a wayward ancient asteroid.

A NASA-affiliated astronomer confirmed Sunday that a golf ball-sized rock that struck a Novato house is the first confirmed piece from the meteor that exploded over the Bay Area Wednesday night.
The 2.2-ounce meteorite hit the roof of Rev. Kent and Lisa Webber on St. Francis Avenue on Thursday night, but they didn't realize at the time what it was, according to Novato Patch.
"I am thrilled," said meteor-tracking astronomer Peter Jenniskens of the SETI Institute in Mountain View, who held the 2.2-ounce meteorite Sunday morning while facing TV cameras in front of the Webbers' home.
"It's wonderful and very interesting to think this might be billions of years old," Rev. Webber said during a break from his Sunday duties at the Presbyterian Church of Novato. "Maybe God's trying to get our attention. I'm not sure what God is trying to say."
Lisa Webber, head nurse in the University of California-San Francisco's medical dermatology department, had heard a boom on Wednesday night followed by the sound of something rolling on her roof.
She didn't make the connection with the exploding meteor until a couple of days later when she read a news account saying that the debris was believed to have fallen along a swath stretching north through Marin County to the Sonoma/Napa area with Novato directly in the path.
"That's when I saw, 'Oh my gosh, I might have a little meteor chunk outside in the yard,'" she said.
Her neighbor's son was home at her moment of realization and recalled from a Discovery Channel show that pieces of meteor should be magnetic.
"So I go find a magnet and it sticks to it, and we both go, 'Whoa!'" she said.
At that point she contacted Jenniskens.
"We propose the name Novato meteorite, pending approval by the Meteorite Nomenclature Committee," according to a post on the website of Jenniskens' group, Cameras for Allsky Meteor Surveillance.
The post includes photos of the impact dent in the roof of the Webbers' home.
Based on the calculated trajectory refined by finding the Novato meterorite, Jenniskens believes it likely that larger fragments fell north-northeast towards Sonoma, according to the Cameras for Allsky Meteor Surveillance website.
According to Jenniskens, the meteor that exploded over the Bay Area was very old, not part of the Orionids meteor shower visible this past week, but an ancient asteroid from the asteroid belt between Mars and Jupiter left over from the birth of the solar system 4.7 billion years ago, the San Francisco Chronicle said.
The Orionid meteors are caused by the Earth pushing through debris left behind by Halley's comet.
Jenniskens was excited about the fundamental secrets that might be unlocked by the Novato meteorite. 
"This means that we have with this meteorite a great track that points back to its origins in the asteroid belt, so with a bit of luck we will be able to say what sort of debris field this rock originated from," he said. "... It will be really interesting to study this and see what this can tell us, either about the origin of the earth or the origin of life."
-
-
Quelle: ElCerritoPatch

Update: 24.10.2012: Meteorit nicht aus dem All sondern nur normaler Stein von der Erde:

Turns out it wasn't a piece of heaven that hit a Novato pastor's home last week.
A chagrined meteor hunter acknowledged Tuesday that what he thought was a meteorite was actually a "natural rock" from Earth.
"I sincerely thought it was, based on what appeared to me was remnant fusion crust," Peter Jenniskens, a scientist at the Seti Institute in Mountain View, wrote on the group's website. "On closer inspection, that crust was a product of weathering of a natural rock, not from the heat of entry."
Jenniskens, who had proclaimed Sunday that the object in question was in fact from outer space, said he had apologized to Lisa Webber, the resident of the home who had found the rock in her yard on Saturday.
Webber had believed that the two-inch rock had struck the roof of the study used by her husband, Kent Webber, pastor at Presbyterian Church of Novato, last Wednesday night. The impact happened just as a meteor exploded dramatically over the Bay Area.
Jenniskens said something definitely hit the Webbers' roof. He said he and Lisa Webber searched the area around her house "in the hope of finding the elusive rock that hit the roof, but no luck, so far."
3844 Views