Scientists Uncover Mars’ “Burrowing” Mystery with New Research

Researchers at Utrecht University are exploring the enigmatic formation of gullies on the Martian surface, suggesting they result from unique “burrowing” actions of carbon dioxide (CO2) ice. This theory, which challenges previous beliefs regarding liquid water shaping the Red Planet’s landscape, is detailed in a recent publication in the journal Geophysical Research Letters.

For decades, scientists have contemplated how narrow channels, known as gullies, formed on Martian dunes. Initial hypotheses indicated that these features emerged from flowing water billions of years ago. Yet, observations from NASA’s Mars Reconnaissance Orbiter shifted the focus to seasonal freezing of CO2 as the primary cause.

Lonneke Roelofs, an Earth scientist at Utrecht University, conducted laboratory experiments to simulate Martian conditions. Her goal was to observe how blocks of CO2 ice interact with the Martian pseudo-regolith. “It felt like I was watching the sandworms in the film ‘Dune,’” she remarked, highlighting the fascinating nature of the research.

The study reveals that for CO2 ice blocks to form on Martian dunes, temperatures must plummet to an extreme -184 degrees Fahrenheit during the winter months. As temperatures rise towards the end of winter, these ice blocks, which can reach lengths of up to three feet, may break off and initiate the burrowing phenomenon. The stark temperature differences between the warming dunes and the cold ice blocks can cause gas to sublimate from beneath them, leading to explosive behavior that displaces sand.

Roelofs and her team utilized the Open University’s “Mars chamber,” a facility designed to replicate the harsh Martian environment. “In our simulation, I saw how this high gas pressure blasts away the sand around the block in all directions,” she explained. This process allows the ice block to dig into the dune, gradually sliding down and forming a gully.

Through various experiments, the researchers adjusted the angles of the dune slopes. When a block of CO2 ice was released from the top of a slope, it began to burrow into the material below, mimicking the action of a mole. “It looked very strange,” Roelofs added, emphasizing the unusual outcomes of their simulations.

As temperatures rise in early spring, the remnants of this burrowing process leave behind only a small hollow in the sand. “Once the blocks reach the bottom of the slope and stop moving, the ice continues to sublimate until all the CO2 has evaporated,” Roelofs noted. The result is a distinct landscape feature that provides insights into the planet’s geological history.

Beyond the quest to uncover evidence of past life on Mars, Roelofs believes that studying other planetary landscapes can yield valuable insights for Earth. By examining the formation of features on Mars, scientists can challenge existing frameworks and pose new questions that may enhance our understanding of Earth’s geological processes.

The research sheds light on both the historical conditions of Mars and the potential for new discoveries that could reshape our understanding of planetary science. As scientists continue to investigate the mysteries of the Red Planet, findings like these contribute to a broader understanding of the universe and our place within it.