Wave-like landforms on Mars offer insights about the planet's icy past, its potential habitability, and the physics of flowing granular materials.
Despite its dry, dusty surface and thinner atmosphere, Mars may have more in common with Earth than scientists previously thought.
In a new study, researchers at the University of Rochester-including PhD student JohnPaul Sleiman and Rachel Glade, an assistant professor in the Department of Earth and Environmental Sciences-and their colleagues found that soil features on Mars look remarkably similar to wave-shaped soil patterns found in Earth's coldest climates. This means that despite their vast planetary differences, Earth and Mars may be shaped by some of the same basic forces and icy processes. The paper, published in the journal Icarus, offers new clues about Mars' past climate and the kinds of environments that might have supported life in the past, as well as new insights into the fundamental physics of granular materials.
The researchers used high-resolution satellite images to analyze nine crater sites on Mars and compared these to sites on Earth. They found that wave-like landforms on Mars have similar shapes and follow the same basic geometric patterns as features called solifluction lobes found in cold, mountainous regions on Earth such as the Arctic and the Rocky Mountains.
These patterns, Glade says, "are large, slow-moving, granular examples of common patterns found in everyday fluids, like paint dripping down a wall."
The biggest difference?
"The Martian versions are about, on average, 2.6 times taller," she says.
The researchers show that this height difference is precisely the number expected if the physical properties of the soil and Mars' weaker gravity allows the lobes to grow taller before collapsing. On Earth, solifluction lobes form when the ground freezes and partially thaws, loosening soil enough for it to slowly creep downhill over time.
Mars likely experienced freeze-thaw cycles resembling Earth, although Martian cycles were likely driven by sublimation-where ice turns directly into a vapor-rather than liquid water-based thawing.
The research suggests that Mars may once have hosted icy conditions that shaped its surface in ways similar to Earth, shedding light on the planet's climate evolution, the potential role of water, and where to look for signs of past life.
"Understanding how these patterns form offers valuable insight into Mars' climate history, especially the potential for past freezing and thawing cycles, though more work is needed to tell if these features formed recently or long ago," Sleiman says. "Ultimately, this research could help us identify signs of past or present environments on other planets that may support or limit potential life."
