During the water debate on Mars, an Australian geologist has stated that the canyons of the red planet were not created by water.
Nick Hoffman of La Trobe University in Melbourne says the cannon was eroded by something similar to the ash cloud that destroyed Pompeii. According to the geologist, liquid carbon dioxide trapped in the subsoil came out of the craters of the soil and, due to the rapid change of pressure, some of the liquid became gas. Then clouds of gas, dry ice, water ice, dust and waste were formed that, moving at full speed, eroded the soil and formed cannons. If the theory is true, we should recognize that Mars has never been a moist planet, at least for the last 3.5 billion years.
Experts have stated that the theory is interesting, but skeptics have appeared. Opposite arguments: that the gas clouds cannot erode such long cannons and that the cannons end in very flat and extensive areas. These characteristics are given by the cannons formed by water, so it is believed that at some point there was water on Mars.
The Australian geologist, however, does not share these arguments. According to him, the formation of the cannons of Mars required a lot of water to be too credible, while with a liter of liquid carbon dioxide 250 liters of gas can be obtained.