It’s not every day that researchers come to your field to look for space rocks.
But that’s what happened to Camrose producer Rod Ross, after a meteor flew across the sky towards his farm on the last evening in August.
“We had a rock that was about 50 kilograms, that might have been about the size of a basketball or a little bit larger, enter the atmosphere,” said Chris Herd, a University of Alberta professor and the province’s leading expert on meteorites.
“The rock was travelling at about 60,000 kilometres an hour when it entered the atmosphere, creating friction so great the rock turns into a fireball, with some of it breaking into pieces that melt.”
When this particular meteor entered the atmosphere on Aug. 31, it was tracked by a camera at Lakeland College at Vermilion.
“It caught the whole thing. We have amateur northern lights photographers with really good cameras from the other side of the trajectory, so we were able to nail down the trajectory,” said Herd.
Footage from peoples’ doorbell security cameras also helped determine the fireball’s path as it travelled from east of Elk Island and to southwest of Camrose — where it imploded about 20 kilometres up (which explains reports of a sonic boom by area residents). The seven-square-kilometre fall zone includes some fields belonging to Ross, who saw the light of the fireball without knowing what it was.
“We have had so many lightning storms that I mistook it as lightning,” he said. “I thought the other possibility was that someone came into the driveway and shone their lights.”
But a day or two later, while driving to work, Ross saw about 15 people on the roadway looking for something. He stopped to find out what they were looking for and began talking to Herd. When told they were looking for meteorites, Ross gave them permission to look on his land, which they did in the second week of September when there were still crops to be harvested.
So far, the search has come up empty — but then again, they’re looking for something pretty small.
“Because we haven’t found anything yet, my suspicion is that we have a single piece or a very small number of pieces that are in a field somewhere, under the crops right now,” said Herd.
Even a one-kilogram meteorite is only the size of a fist and since they have a black crust (from the high heat generated when passing through the atmosphere), they’d be very difficult to spot.
“Basically, we’re looking for a black rock sitting in, or punched into the soil in someone’s field,” said Herd. “The most common have a bit of iron, nickel, metal and metallic pieces throughout them, which makes them more dense than a typical rock on the surface of the Earth.”
That also means they are attracted to magnets, which searchers use to locate them.
Herd’s team is now waiting for harvest to be completed before heading back for another search. He has permission from Ross to go on his land, and anyone wanting to search for a meteorite on private land would need to do the same.
“Farmers have complete control of their property,” said Herd. “If a meteorite is found on their property, it belongs to them.”
Ross has done some media interviews, and is excited about the possibility of a meteorite being found.
“The media attention has been funny,” said Ross, who has taken to joking he hopes the meteorite isn’t Kryptonite as his secret Superman identity will be revealed.
Although the researchers are searching for a needle in a haystack, he said, he hopes they’re successful because — he has learned — that meteorites have considerable scientific value.
If found, scientists can learn more about the geology of the asteroid it came from, which helps further understanding of Earth’s geology.
But they need to find it fairly quickly, before moisture and contact with soil affect it.
“The more pristine it is, the more it retains the characteristics of the rock when it was in space… (and) less contaminated by this stuff at the Earth’s surface,” said Herd, who has a video to help people determine if they’ve found a meteorite.
He also curates a meteorite collection at the university, some of which have come from farmers’ fields. They’re typically named after the place where they are found, and Herd is hoping the Camrose meteorite will be part of that collection.