An article published in the journal “Geophysical Research Letters” describes a research on silica halos discovered in the lower areas of the northern slopes of Aeolis Mons in the Gale Crater on Mars. A team of researchers led by Jens Frydenvang used the information gathered by NASA’s Mars Rover Curiosity to try to figure out for how long there was liquid water, concluding that the needed conditions lasted longer than expected.
The presence of liquid water on the surface of the planet Mars when it was young is now established but we’re talking about a period that was thought to have ended nearly 3.8 billion years ago. After an era in which Mars had a dense atmosphere and conditions similar to those on Earth, the environmental collapse slowly turned it into the planet we know today.
In the course of 2015, the Mars Rover Curiosity discovered the presence of high concentrations of silica in an area of Gale Crater, a mystery to mission scientists. This new research seems to indicate a history of the Martian environment somewhat different from the known one for the links of silica with the presence of liquid water.
The silica examined in this research was found at an altitude of around 20-30 meters near sediments of ancient lakes. Jens Frydenvang, a Curiosity team scientist at the Los Alamos National Laboratory and the Danish University of Copenhagen, pointed out that the location of silica in paler halos of younger rocks indicates that it was brought there from older rocks by the water that flowed through the fractures.
Even when the lake finally evaporated, substantial amounts of water were present much longer than expected. The Mars Rover Curiosity’s Chemistry and Camera (ChemCam) instrument used to analyze the halos some time ago made it possible to discover that there’s boron in the area, the first time that this element was discovered on Mars’ surface. Boron is associated with sites where a lot of water evaporated, a further indication of the ancient events of that area.
If water remained in liquid form for a longer time than expected, this means that life-supporting conditions also lasted longer, at least in that groundwater. There are still many unknowns and at the moment it’s impossible to determine if life forms ever actually developed.
It’s actually possible that for other reasons even in that groundwater there were other conditions that prevented the survival of any possible life forms. The study of the data collected by the Mars Rover Curiosity continues to better understand the evolution of that environment and its habitability potential.