The origin and nature of Mars are mysterious. The planet has geologically distinct hemispheres with smooth lowlands in the north and cratered, high-elevation terrain in the south. The red planet also has two small oddly-shaped oblong moons and a composition that sets it apart from that of the Earth.
New research by CU Boulder professor Stephen Mojzsis outlines a likely cause for these mysterious features of Mars: a colossal impact with a large asteroid early in the planet’s history. This asteroid—about the size of Ceres, one of the largest asteroids in the solar system—smashed into Mars, ripped off a chunk of the northern hemisphere and left behind a legacy of metallic elements in the planet’s interior. The crash also created a ring of rocky debris around Mars that may have later clumped together to form its moons, Phobos and Deimos.
The study appeared online in the journal Geophysical Research Letters, a publication of the American Geophysical Union, in June.
“We showed in this paper—that from dynamics and from geochemistry—that we could explain these three unique features of Mars,” said Mojzsis, a professor in CU Boulder’s Department of Geological Sciences. “This solution is elegant, in the sense that it solves three interesting and outstanding problems about how Mars came to be.” [More at links]