Call it a message from heaven, but the first meteorite reported from the Oct. 17 fireball that lit up the sky over the San Francisco Bay area struck the roof of the Rev. Kent and Lisa Webber’s home in Novato’s Pleasant Valley neighborhood. Kent is pastor of Novato’s Presbyterian Church. Lisa works as the head nurse at the Department of Dermatology of the University of California, San Francisco Medical Center.
While relaxing at home last Wednesday night watching TV, she heard a boom and then something rattling around on the roof. She walked outside for a look, but didn’t find anything amiss … at first.
Later last week, Lisa’s curiosity was piqued by Dave Perlman’s article in the San Francisco Chronicle on Saturday, describing the NASA/CAMS meteor trajectory predicted impact area centered on Novato. Lisa decided to make a more thorough search and turned up an unusual rock near her side gate. A neighbor’s son suggested she test it with a magnet. She did and it stuck! Not a guarantee of a meteorite but a very good sign all the same.
Webber contacted Dr. Peter Jenniskens, who runs NASA’s Cameras for AllSky Meteor Surveillance or CAMS, an automated video surveillance program of the night sky in search of meteors.
Two CAMS cameras in different locations in the Bay area triangulated the fireball’s path. Based on the picture data, Jenniskens predicted a potential landing zone in funnel-shaped zone east of San Rafael, over Novato and toward Sonoma.
He and the Webbers’ neighbor Luis Rivera inspected the roof and found an impact pit or divot in a shingle that matched up nicely with the meteorite’s size. Usually the smallest meteorites drop first with the larger ones moving farther ahead before they fall too. Because the fireball traveled from SW to NE, Jenniskens thinks it likely larger fragments dropped nearer Sonoma northeast of Novato.
“The significance of this find”, says Jenniskens, “is that we can now hope to use our fireball trajectory to trace this type of meteorite back to its origins in the asteroid belt,” said Jenniskens. The find also helps start the process of defining the orientation and location of the meteorite drop-zone or strewnfield.
Rain’s expected in the area today – something meteorites don’t like. Rain makes for rust and breakdown by erosion. Jenniskens hopes more of the space bounty comes to light before a soaking. If you’re in the area and think you’ve found a fragment of cosmic rock, contact him at this e-mail: Petrus.M.Jenniskens@nasa.gov
By the way, you’ll still see stories claiming this meteorite came from the weekend Orionid meteor shower. It didn’t. The fireball blew in from a completely different direction opposite Orion.
I want to thank Dr. Jenniskens for pictures and information from the CAMS site used for this article.
** UPDATE Oct. 23, 2012 — The rock is not a meteorite after all! As per Peter Jenniskens:
“We examined the rock with a petrographic microscope yesterday, says Jenniskens, and quickly concluded it was not a meteorite. I sincerely thought it was, based on what appeared to me was remnant fusion crust. On closer inspection, that crust was a product of weathering of a natural rock, not from the heat of entry.” He searched the ground again with Lisa Webber but failed to a meteorite. So how did that hole get in that roof shingle?