ملفات اخبار العرب24-كندا: A screenshot of University of Alberta professor Chris Herd sharing tricks of the trade on how to spot a real space rock in a video on the university’s meteorites website. (University of Alberta)
A meteor streaked across the sky above Edmonton on Saturday night and now rock hunters are looking for any trace of the space rock that fell possibly southeast of the city.
Chris Herd, professor of earth and atmospheric sciences at the University of Alberta, who is also the curator of the U of A's meteorite collection, said he gets six to ten inquiries a month from people who think they've found a space rock. But 99.9 per cent of the time, it's not a genuine meteorite.
"So there are a lot of rocks out there that look like what we call the 'meteowrongs'," Herd said in an interview on CBC Edmonton's Radio Active on Wednesday. "That look like meteorites, but are not."
Fireballs in the Edmonton area have been spotted numerous time recent years, and as recently as January, but meteorites actually falling to the earth in the area are rare.
In 2008, meteorite pieces were found south of Lloydminster in a place called Buzzard Coulee, after a big fireball was spotted over the area.
Dash and doorbell cameras across Edmonton captured the bright mass on Saturday night, but there were only a few observations from cameras with good calibration, Herd said.
"Where we know what the trajectory was against the background of stars," he said. "You need up to ideally three observations from different angles to literally triangulate that trajectory and then figure out where the rocks, the meteorites, may have landed.
Experts are still trying to determine where it ended up landing, but New Sarepta, a hamlet about 50 kilometres southeast of Edmonton, has been identified as the probable endpoint of the fireball.
"These rocks continue to the ground in what's called dark flight," Herd said. "They're no longer glowing on the outside from about 20 kilometres up so the distance from that point to the ground is still a fair ways. It could be tens of kilometres."
What to look for
One of the specific things to look for is if it feels heavier than expected, because most common meteorites have a bit of metal in them, which makes them denser, Herd said.
For the same reason, a meteorite should be magnetic.
If it has holes or bubbles in it, it's almost certainly not a meteorite, which will have a dark crust, also known as a fusion crust, formed by its journey through the atmosphere.
"The outside has essentially melted in and wrapped this rock in a glass basically," Herd said. "And typically where that flakes off, you'll see the inside and it looks sort of like a cement … So think of a chunk of cement with black crust on the outside."
The U of A has an online reporting system for meteors, where people can fill out a form and upload photos of the rock sample they found to be reviewed by experts at the university.
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