On January 18, 2000, a meteorite crashed into Tagish Lake, just over the border from the Yukon and into northern British Columbia. The cosmic rock lit up the morning sky as it fell, causing loud bangs and dust clouds to waft into the upper atmosphere. But the fact that it fell into the northern lake’s icy depths also offered some luck.
“It’s one of those rare occurrences,” says post-doctoral research fellow Lee White, with the Royal Ontario Museum (ROM). “The special thing about this meteorite is that it landed on an ice flat and has never been above room temperature. It hasn’t had the chance to melt.”
Scientists were able to collect fragments of the 105-tonne rock and bring some of it to ROM, which houses Canada’s most diverse range of meteorite shards.
White explains that meteorites may fall in places like North-Western Africa, where it’s easy to spot the rock’s black sheen within the sand. But that environment also has its drawbacks.
“It gets really hot in the day and really cold at night,” explains White. “The atmosphere gets into the rock and it becomes altered. But because we don’t know how long they’ve been there for, we don’t know if [the changes to the rock] happened in space or here on Earth.”
In this case, scientists know conclusively the environment had no effect on the Tagish Lake meteorite’s composition.
“It would be the same as if we had billions of dollars to go to an asteroid, collect it and bring it back,” says Chris Herd, a professor and curator for the University of Alberta’s meteorite collection.
Herd also researched how some Tagish meteorite fragments showed evidence that water flowed through the asteroid it was once a part of 4.5 billion years ago.
“There’s no water left, but it has certain compounds in it that are important for forming life,” he says.
Scientists are using the atom tomography method—which allows them to examine atoms and pull apart a sample 1/1000th the width of a human hair—to examine the minerals that may have formed water on the parent asteroid.
“This revealed an abundance of sodium atoms, which suggest the original water would have been sodium rich and alkaline, which is a critical piece of evidence for how quickly amino acids, the building blocks of life, could form,” White says.
As an added bonus, the fact that this meteorite fell in Canada means it’s Canadians who are doing the breakthrough research.
“By showing that Canada can do this type of analysis, we’re positioning ourselves as a world leader for this type of study,” says White.
The methods and tools being used—from the tomography method to the unique glove box that fragments are handled in—is even drawing eyes from NASA. It’s also a chance to add another piece to the puzzle in understanding how life began.
“It allows us to do things we never dreamed of before,” says Herd.
