BOULDER, Colo – Mars likely got its distinct geography and mineral makeup from the impact of a massive asteroid that hit the planet billions of years ago, according to new research from a CU Boulder scientist.
Geology professor Stephen Mojzsis teamed up with astronomer Ramon Brasser at the Earth-Life Science Institute at the Tokyo Institute of Technology to produce the research, which was published in the journal Geophysical Research Letters last month.
The two researchers looked at the so-called “single impact hypothesis,” which scientists first proposed more than 30 years ago. The hypothesis states that an impact from a large asteroid could explain the differences in elevation between Mars’ northern and southern hemispheres.
It could also explain the presence of rare metals in Mars’ mantle that usually are found in rocky planets’ cores.
Mojzsis and Brasser used computer simulations to test the hypothesis, trying different sizes of asteroids to see which one was most likely to distribute metals in the amounts found on Mars.
They found that the Mars’ mineral composition is most likely the result of an asteroid about 745 miles across smashing into the planet about 4.43 billion years ago. That impact was then likely followed by a series of smaller collisions over many years.
An impact of that size likely also sent a cloud of debris into orbit around Mars – debris that would eventually clump together to form the planet’s moons, Phobos and Deimos.
Mojzsis said his and Brasser’s findings fit well into current understandings of planet formation and do a good job of explaining how Mars came to look the way it does now.
“This solution is elegant, in the sense that it solves three interesting and outstanding problems about how Mars came to be,” Mojzsis said.