Could carbon dioxide, not water, have shaped the Red Planet?

For decades, scientists have believed water carved Mars' dramatic landscape. Massive river valleys, ancient deltas, and complex geological formations seemed to prove the planet once flowed with liquid water. However, a new theory challenges this long-held assumption, suggesting that liquid carbon dioxide rivers might be the true sculptor of Mars' surface.

The theory claims that under the planet's early atmosphere, carbon dioxide could have liquefied and flowed across the terrain. If true...