Clay on Mars could have formed due to planet's crust, not water: Study

Researchers have actually found evidence of ancient phyllosilicates, or clays, on the Martian surface. If proved true, this latest news can rewrite the early history of the Red Planet.

Mars trip 2018
The planet Mars is shown May 12, 2016 in this NASA Hubble Space Telescope view taken May 12, 2016 when it was 50 million miles from Earth. Earth's neighbor planet makes its closest approach in a decade this month, providing sky-watchers with a celestial show from dusk to dawn. Reuters

A new research, published in the journal Nature, has revealed that clay minerals could have formed on Mars during the creation of the Martian crust itself, long before any water flowed on the planet. Scientists have actually found evidence of ancient phyllosilicates, or clays, on the Martian surface. If proved, this latest news can rewrite the early history of the Red Planet.

"One of the complications that comes up in Mars evolution is that we can't create a scenario where surface weathering had the capacity to produce the extent of mineral alteration that we see," Jack Mustard, Professor at Brown University in the US and study co-author, said.

Experts say that phyllosilicates are generally formed by the interaction of water with volcanic rock. This fact eventually leads us to believe that there must have been some sustained surface water, groundwater or active hydrothermal systems at some point in Martian history.

However, the new scenario offers offers a means of creating widespread clay deposits that does not require a warm and wet climate or a sustained hydrothermal system on early Mars.

The researchers, who were backed by lab experiments and computer models, revealed out how the scenario would have worked. Mars and other rocky planets are thought to have been covered by oceans of molten magma in the very early solar system. The researchers believe that as the Mars magma ocean began to cool and solidify, water and other dissolved volatiles would be outgassed to the surface, forming a thick, steamy atmosphere surrounding the planet.

In this process, the moisture and heat from that high-pressure steam bath would have converted vast swathes of the newly solidified surface to clay. But, as Mars evolved over a period of billions of years, the volcanic activity and asteroid bombardments would have covered the clays in some places and excavated them in others. Scientists believe that this eventually lead to the widespread but patchy distribution seen on the surface today.

The researchers have further synthesized rock samples matching the composition of Martian basalt to demonstrate that the mechanism they propose is plausible. They have used a high-pressure device to recreate the temperature and pressure conditions that may have been present amid the steam atmosphere created by a magma ocean.

The researchers cooked samples for nearly two weeks and they checked whether there was any alteration in it. "It was really remarkable how quickly and extensively this basalt was altered," lead researcher Kevin Cannon, a postdoctoral researcher at the University of Central Florida told IANS.

The researchers added that the steam atmosphere associated with a magma ocean could have survived for as long as 10 million years or more.

Source: IANS

This article was first published on December 7, 2017