New Insights Challenge Water Theory Behind Martian Gullies
By Editor • September 14, 2026 • 2 min read
Recent research has reshaped our understanding of Martian gullies, suggesting that they may not have formed due to liquid water as previously thought. Instead, a team of French astrophysicists has provided compelling evidence that frozen carbon dioxide could be the primary agent behind these intriguing geological features.
Debunking the Liquid Water Myth
Since the discovery of gullies on Mars, scientists have speculated about the presence of water on the planet, particularly after NASA's Mars Global Surveyor sent back images of these formations. However, in 2014, NASA revealed that the gullies were much younger than expected and attributed their formation to the seasonal freezing of carbon dioxide, also known as dry ice. This revelation prompted a shift in research focus, leading scientists to investigate how exactly frozen CO₂ contributes to the formation of these gullies.
New Findings from the Martian South Pole
In their latest study, the researchers concentrated on the Sisyphi Cave region near Mars' south pole, where a network of gullies exists. Their analysis indicated that not only is the role of liquid water unlikely, but CO₂ geysers, previously thought to be a potential explanation, also do not seem to be responsible for these formations. Instead, the researchers propose that the gullies are shaped by CO₂-ice-driven processes such as fluidization or avalanches occurring during the latter stages of seasonal ice sublimation.
Understanding the Mechanism Behind Gully Formation
The study highlights that there is a temporal disconnect between the formation of gullies and the activity of CO₂ geysers. While geysers create dark spots on the Martian surface, these appear significantly earlier than the gullies, complicating any direct relationship between the two phenomena. One possible mechanism suggested involves turbulent carbon dioxide gas bubbles acting as a lubricant, allowing a mixture of dry ice and dust to flow and carve out the gullies.
Source: gizmodo.com
