quinta-feira, 4 de outubro de 2012
Touch a 4.5 billion-year-old meteorite in Bradenton, Florida
It likely exploded upon slamming into the atmosphere, and the disintegrating fireball blistered a 36-square-mile tract of prehistoric plains with a dozen craters.
The first reports of its aftermath were not logged until 1576, when skeptical Spanish conquistadors investigated apocalyptic native folklore about fire raining from the sky. The trail led to a treasure trove of scattered and often massive meteorite fragments weighing up to 16 tons. The impact zone is called Campo del Cielo, and it has become a windfall for scientific research.
On Friday, one of those cosmic remnants will go on permanent display at the South Florida Museum in Bradenton, and the public is invited to take a look.
Measuring 18 inches long and 10 inches tall and weighing in at 138 pounds, the extraterrestrial rock is nicknamed FeNi for its composition, mostly iron with traces of nickel. The arrival of FeNi has museum staffers jazzed.
“I like putting my hand on something that came from outer space during the earliest part of the solar system, which is made of the same material at the core of the Earth,” says astronomer Jeff Rodgers, director of the Museum's Bishop Planetarium.
“I can't go to the stars. I can't go to the planets. But I can touch something that's 4.5 billion years old. I think it's safe to say this is the oldest thing any of us will ever come in contact with.”
To generate interest, the first 500 children who visit the museum on Friday evening will receive free meteorite particles. Unlike FeNi, glazed to a fine sheen with mineral oil to prevent oxidation, the take-home samples could be mistaken for common rust fragments. These fragments, however, trace their ancient origins to a failed planetoid system between Mars and Jupiter known as the Asteroid Belt.
“Who knows what that might inspire?” says Rodgers. “Nobody ever sent me home with chunks of meteorites when I was a kid.”
FeNi, and its sister piece — a similar-sized meteorite being held for now in museum storage — is a gift from board member Jim Toomey, a Bradenton paleontologist who runs the nonprofit Toomey Foundation for Natural Sciences.
Toomey decided to bring space debris to Bradenton last year after sizing up the “public fascination” with a hands-on meteorite display at the Lowell Observatory in Flagstaff, Ariz. “In science, it's important for people to touch and handle material” to connect with it, he says.
Toomey will not say how much he paid for FeNi and its companion, but licensed meteorite dealers sell iron-based specimens for between 50 cents and $5 a gram. Meteorites with less common elements can command between $2 and $20 a gram.
Although the odds against discovering a meteorite the size of FeNi are ridiculously high, Rodgers says Earth is bombarded by approximately 200,000 tons of natural space debris each year.
“I'd be willing to guess within Manatee County's borders, there are tons of meteoritic material,” he says. “If you see a rock that looks a little unusual, the first test is to put a magnet on it and see if it sticks — then we'd have reason to believe it might be unique.
“But most of it comes in the form of dust. In fact, 30 percent of the dust you sweep up at home is of extraterrestrial origin. Which makes cleaning your house a lot sexier.”
Far from being a publicity stunt, the FeNi display will serve as a conversation-starter for the entire museum, according to exhibitions and collections director Matthew Woodside.
“This will create a standalone exhibit in the lobby that serves as a pathway to all our other display nodes,” Woodside says. “So we'll have the oldest stuff in the solar system, a 65-year-old manatee, and everything else in between.”
Publicado por Jorge M. Gonçalves às 6:44 da tarde