The Mistastin crater on Earth holds large quantities of the bright white rock on the majority of the moon’s surface
Much like most of my dating life, the remote location of the crater is isolated from most humans and mimics the aloneness felt on the moon; the structure is similar to what you’d find for many lunar craters; and the area contains rare rocks that are eerily similar to what astronauts find on the moon.
Those qualities make it a suitable training ground for potential astronauts of NASA’s Artemis mission, which plans to land astronauts on the moon as early as 2025. On Wednesday, NASA took a significant step toward returning to the moon and launched an un-crewed test flight called Artemis I, which will not land on the surface but stay in lunar orbit for up to 25 ½ days to demonstrate the rocket and spacecraft can fly safely.
“This crater in Labrador wasn’t even known to be a crater during the Apollo missions,” said Gordon Osinski, a planetary geologist at Canada’s Western University who has guided astronauts around the crater. “I’d love to see every astronaut who eventually walks on the moon come to Mistastin.”
Mistastin, known locally as Kamestastin, lies on the spiritual and traditional hunting grounds of the Mushuau Innu First Nation and requires approval from them to visit.
The crater is essentially in the “middle of nowhere” said planetary geologist Cassandra Marion, who has been to the site six times. There’s no formal runway strip, and visitors usually land in a small unpressurized cargo plane on a shrubby gravel area — if there’s not a large boulder in the way. It’s often rainy and windy. When it’s not windy, it’s buggy with loads of biting black flies.
Located in the Canadian Arctic, the rugged terrain is a mix of taiga and tundra. Black spruce and Alder trees live at lower elevations, while moss appears near riverbeds and at higher elevations. And then there’s small delicious blueberries everywhere in the tundra. If you don’t watch where you sit, Marion said you may get up with “purple butt.”
“She’s a cruel mistress, in a sense, but I would go back” Marion said. “It’s one of the most beautiful places that I’ve been to. You feel like you’re the only ones there for kilometers at a time.”
In September, Marion and Osinski took two astronauts to the Mistastin crater for geology training, and to identify rocks they might see on the moon. A lot of the rocks are accessible through outcrops, or cliff faces, that emerged millions of years ago.
The Mistastin crater formed when an asteroid crashed around 36 million years ago and left a sizable 28-kilometer dent in the ground seen today. Osinski said such large craters, like this one, are called “complex craters” and are common on the surface of the moon.
Complex craters are shallower and flatter, instead of a bowl-shaped depression like Arizona’s Meteor Crater where astronauts also train. Like many lunar complex craters, Mistastin also has a mountain in the middle called a central peak.
“This crater in Labrador is not only a complex impact crater, it’s relatively well-preserved,” Osinski said. “I’ve been to it many times and it’s still really neat when you walk uphill to the rim and then just literally peer into this massive hole in the ground.”
We know being at Mistastin crater isn’t exactly like the moon. Unlike the moon, we have wind, water and WiFi. In fact, the modern-day Mistastin may seem like it bears no resemblance to the moon because it contains a lake (spanning about half the size of the initial crater impact), likely a result of drained glaciers from the last Ice Age. But don’t let the lake fool you.
A large similarity to our lunar friend lies in its rocks. It is one of two craters on Earth to contain large amounts of a rock called anorthosite. The other is the significantly eroded Manicouagan impact structure in Quebec, making the much younger, better preserved Mistastin crater the preferred choice for research and astronaut training.
While anorthosite is rare on Earth, it’s common on the lunar surface. You may have never pronounced its name, but you’ve seen it every time you look up at the moon: The rock is the light-colored, highly reflective parts seen widely across the moon’s surface called the lunar highlands.
“Part of the reason why we see so much around the moon is just the way that the moon formed,” said Julie Stopar, a lunar geologist at the Lunar and Planetary Institute at the Universities Space Research Association.
Compared to our home planet, the moon’s surface was mainly sculpted through impact cratering and volcanism.
According to a popular formation theory, the moon came together when a Mars-sized body crashed into a young Earth near the beginning of our solar system formation about 4.6 billion years ago. Stopar said hot debris around the Earth coalesced into the moon, covering the young moon in a magma ocean — “basically just lava, lava everywhere.”
In a simplified explanation, Stopar said that as the surface magma ocean cooled over time, different minerals and rocks began to crystallize out. Denser materials sank, and lighter materials floated to the top to essentially become the surface of the moon. A prevalent mineral to float to the surface was anorthite, which is the predominant component in anorthosite rock.
The origin story of anorthosite on Earth is more complicated and not as well understood, said Marion, who serves as a science adviser at the Canada Aviation and Space Museum. Research suggests the anorthosite is also likely formed due to separation of lighter crystals in magma, but deep within our mantle. As the magma slowly cools and crystallizes, the less dense mineral crystals separated from denser materials and solidified to form anorthosite. The rock emerged to the surface through erosion and plate tectonic activity.
Then, the fact that an asteroid just happened to create a crater in this rare anorthosite-rich area? Well, that’s nature’s luck.
The collusion brought high temperatures and pressure, which essentially fractured the rocks, broke them up and melted them. Marion said the effects of the high velocity impact are similar to a large impact on the moon.
“How the rocks have changed are similar to how they would have changed on the moon after an impact,” Marion said.
Marion points out that anorthosite is present across this region in Labrador, even if you can’t go to the crater itself.
Astronauts who travel to the moon will photograph various types of rocks, such as melt rocks, and provide notes to help researchers like Osinski back on Earth.
“They can’t bring back every rock they see. We want them to do that mental sorting of, ‘Okay, I’ve got 100 rocks in front of me and I can bring back two’ [and] how do you go about choosing that in real time, essentially,” Osinski said.
Stopar said if the astronauts can bring back more moon rocks, then researchers can date craters on the moon and create a better geologic history of our neighbor and floating debris at the beginning of our solar system. She said we can also learn how much water was delivered to the Earth and moon from comets and asteroids and any challenges to life at that time.
“I’m really excited about seeing this kind of exploration happening,” said Stopar, who is a team member of NASA’s Lunar Reconnaissance Orbiter mission. “Scientifically, I know it’ll be great because anytime we get samples of the moon, we just learn so much more about it. Even today, we’re still learning tons about the moon from the samples that were brought 50, 60 years ago now.”