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A team of planetary scientists has developed a promising new way to peer beneath the dusty surface of Mars and other planetary bodies.

A new study finds that ejecta blankets—the layers of rock and other material blasted out of a crater by an impact—can vary in size depending upon what materials are present beneath the impact point. The insight could help scientists spot buried glaciers and other important subsurface features using data from orbital satellites, the researchers say.

"Historically, researchers have used the size and shape of impact craters to infer the properties of materials in the subsurface," said Aleksandra Sokolowska, a UKRI fellow at Imperial College London. "But we show that the size of the ejecta blanket around a crater is sensitive to subsurface properties as well. That gives us a new observable on the surface to help constrain materials present underground."

Sokolowska performed the work while a postdoctoral researcher at Brown University, working with Ingrid Daubar, an associate professor (research) in Brown's Department of Earth, Environmental and Planetary Sciences and study co-author. The research is in the Journal of Geophysical Research: Planets.

Impact craters are everywhere in the solar system, pocking the surfaces of all planets and moons with solid surfaces. Scientists have long looked at the size and shape of craters for clues about what might be beneath the surface. The strength of the subsurface, how porous it is and a host of other factors can alter crater characteristics. That gives scientists a way to peer into planetary interiors from orbit, without having to land a spacecraft on the surface.

For this new research, Sokolowska wanted to see if crater ejecta might provide another source of information. To do that, she used computer simulations—co-developed by Gareth Collins, a professor at Imperial College London and study co-author—that capture the physics of planetary impacts.

In the simulations, Sokolowska could vary the characteristics of the material far beneath the surface to see how it might affect the distance ejected debris travels. She tested a variety of different subsurface materials: solid bedrock, sediments like those that might be found in a buried lake bed, loose rock mixed with ice and solid glacial deposits, among others.

The simulations showed that different subsurface materials and layering patterns produce a wide range of different ejecta patterns.

"The differences in ejecta radius can be quite large, and we predict that they could be measured from orbit with the HiRISE camera onboard Mars Reconnaissance Orbiter," Sokolowska said. "Once the method is thoroughly tested, it could become a promising new tool for investigating subsurface properties. Turning this proof-of-concept work into a tool is the subject of my current fellowship at Imperial."

To add some ground truth to the simulation results, the team looked at two fresh impact craters on Mars. Because the craters are fresh, their ejecta blankets haven't been eroded much, making it relatively easy to measure their original size.

The researchers also had some idea from data that one of the craters was located over solid bedrock, while the other was known to have some subsurface ice. Consistent with model predictions, the crater on the icy subsurface had a much smaller ejecta blanket than the one on bedrock.

The findings help confirm that differences in ejecta radius are detectable and reflect known subsurface properties.

The method could be useful for several current and upcoming spacecraft missions, the researchers say. In February 2026, the European Space Agency's Hera spacecraft will arrive at Dimorphos, an asteroid that NASA hit with a projectile several years ago to test the possibility of deflecting asteroids that could be headed for Earth. Hera's mission is to look at the crater made by the deflection test to learn more about the asteroid's interior.

"Our work suggests that ejecta that did not escape from the asteroid and blanketed its surface could hold valuable information about the asteroid's interior," Sokolowska said.