Instead of water, a steam-laden or supercritical atmosphere could have allowed the formation of clay on the surface of Mars, according to research published on Wednesday. The preponderance of clay on the Martian surface has often been associated with the presence of water as well, even if it was billions of years ago.
There is a large amount of clay on the surface of our neighboring planet, and its distribution is widespread but uneven. It is usually found as ancient outcrops of phyllosilicates that add up to thousands on the red planet, and its association with water flow is explained by the way clay is formed. Take three ingredients: rock, heat and water. Most commonly, clay forms when water comes in contact with volcanic rock.
But a new investigation by Kevin Cannon ̵
Like other rocky or terrestrial planets in the solar system, it is believed that Mars was covered by a global ocean of magma or molten rock. When it began to cool and become solid, dissolved volatiles, including water, were probably expelled and formed a thick atmosphere around the planet. This dense layer of vapor, with its moisture and high pressure, could have turned large portions of the new solid surface into clay. Over time, the bombardment of asteroids and volcanic activity would lead to cover the clay in some places and expose it to others.