EDMONTON — Researchers at the University of Alberta and their colleagues from around the world have identified the specific locations from which most of the approximately 200 Martian meteorites originate. They’ve traced the meteorites to five impact craters within two volcanic regions on the Red Planet called Tharsis and Elysium.
“This will fundamentally change how we study meteorites from Mars,” says Chris Herd, curator of the U of A’s Meteorite Collection and professor in the Faculty of Science. “The idea of taking a group of meteorites that were all blasted at the same time and then doing targeted studies on them to determine where they were prior to being ejected — that to me is the exciting next step.”
Martian meteorites find their way to Earth when something hits the surface of Mars hard enough that material is “blasted off the surface and accelerated fast enough to leave Mars’ gravity,” says Herd. This ejected material launches into space, ends up in an orbit around the sun, and some pieces eventually fall to our planet as meteorites. The blast leaves an impact crater on Mars’ surface. This happened 10 times in Mars’ recent history.
“We think we’ve found the source craters for half of all 10 groups of Martian meteorites,” says Herd.
He says that scientists’ improved understanding of the physics of exactly how the rocks are ejected from Mars was key to this finding. Previous attempts to determine the precise sources of Martian meteorites were met with limited success, making this a notable breakthrough.
“Now, we can group these meteorites by their shared history and then their location on the surface of Mars prior to coming to Earth,” Herd says.
More knowledge about how and where on Mars these meteorites originate gives us additional insight into the samples we already have on Earth. The ability to contextualize and position these samples within the Martian geological record for the first time “will enable the recalibration of Mars’ chronology, with implications for the timing, duration and nature of a wide range of major events through Martian history.”
“It is really amazing if you think about it,” says Herd. “It’s the closest thing we can have to actually going to Mars and picking up a rock.”
The study was published in Science Advances.
More information can be found here. To speak with Chris Herd, please contact: Andrew Lyle U of A communications & marketing partner, Faculty of Science alyle@ualberta.ca