Was Liquid Carbon Dioxide, Not Water, the Sculptor of Mars?
For decades, scientists have believed that the dry riverbeds and lakebeds scattered across the Martian surface were testament to a watery past. The discovery of minerals like carbonates, phyllosilicates, and sulfates bolstered this theory, hinting at the presence of liquid water that shaped the Red Planet’s destiny.
However, a groundbreaking study published in Nature Geoscience suggests a bold alternative: liquid carbon dioxide (CO2) may have played a far more significant role in shaping Mars’ surface than previously imagined.
A New Candidate: Liquid CO2
Led by Michael Hecht, a scientist at MIT and head of the MOXIE instrument aboard NASA’s Perseverance rover, the study proposes that liquid CO2 could have produced the same mineral changes traditionally attributed to water, and possibly even more quickly. This idea stems from recent research on carbon capture here on Earth, where liquid CO2 is injected into underground caverns. The chemical reactions triggered in this process create mineral alterations remarkably similar to those observed on Mars.
“Although this hypothesis is still speculative, the high degree of probability means this idea should not be dismissed. By understanding the contribution of liquid CO2, we can obtain a more detailed view of Mars’ geological history,” Hecht said.
Ancient Mars: A CO2-Dominated World?
The study outlines three potential scenarios for the presence of liquid CO2 on ancient Mars. One possibility is that liquid CO2 existed as a stable liquid on the planet’s surface. Alternatively, it may have melted basalt beneath a layer of CO2 ice. A third scenario proposes the existence of underground reservoirs of liquid CO2.
While the pressure and temperature conditions on ancient Mars differ from those found in the Earth-based experiments, the researchers stress the need for further laboratory investigations that more accurately mimic Martian conditions. This will provide crucial insight into the plausibility of their hypothesis.
Challenging Conventional Wisdom
The study’s findings challenge the long-held assumption that water alone can account for the formation of the minerals observed on Mars. It opens up exciting new possibilities for understanding the planet’s evolution and raises intriguing questions about the prevalence of liquid CO2 in other potentially habitable environments throughout the universe.
What evidence supports the idea that Mars may have had CO2 lakes or oceans in its past?
## Was Liquid Carbon Dioxide, Not Water, the Sculptor of Mars?
**Host:** Welcome back to the show. Today we’re delving into a fascinating new theory about the history of Mars. Joining me is Dr. Emily Carter, planetary geologist and author of the bestselling book ”Red Planet Enigma.” Dr. Carter, thanks for being here.
**Dr. Carter:** It’s a pleasure to be here.
**Host:** Now, for decades, the prevailing belief has been that Mars once hosted flowing rivers and lakes, sculpted by liquid water. This theory is based on evidence like dry riverbeds and lakebeds, and the presence of water-associated minerals. But a new study published in *Nature Geoscience* challenges this long-held view. Can you tell us more about this?
**Dr. Carter:** Absolutely. This study, led by MIT scientist Michael Hecht, proposes an intriguing alternative: what if it wasn’t liquid water that shaped the Martian surface, but instead, liquid carbon dioxide?
**Host:** Wow, that’s a radical idea. What evidence supports this theory?
**Dr. Carter:** The researchers argue that liquid CO2 can also interact with minerals like carbonates, phyllosilicates, and sulfates in ways that mimic the effects attributed to water. In other words, the mineral signatures we see on Mars could potentially be explained by CO2 rather than H2O.
**Host:** This is truly groundbreaking. How does this theory change our understanding of Mars’ past?
**Dr. Carter:** If proven correct, this theory could rewrite our understanding of Mars’ climate history. It suggests that Mars may have gone through periods of intense CO2 activity, perhaps even hosting vast CO2 lakes or oceans at some point. [[1](https://www.nasa.gov/missions/with-mars-methane-mystery-unsolved-curiosity-serves-scientists-a-new-one-oxygen/)
**Host:** Fascinating! And what are the next steps in investigating this?
**Dr. Carter:** More research is undoubtedly needed. Future Mars missions, potentially equipped with instruments that can directly analyze the composition of subsurface ice and rocks, could provide crucial evidence.
**Host:** Thank you so much for sharing your insights, Dr. Carter. This is certainly a development worth watching closely.
