NASA probe discovery suggests Mars once had clean water
Nearly a decade ago on a mission to Mars, the Opportunity spacecraft has found clay minerals in a rock that clearly indicate that "drinking" water has already flowed into the Red Planet, probably at some point in its first billion years of existence. This rock was discovered near a crater known as Endurance, and the clay contained therein was formed in a chemically favorable environment for the emergence of life.
According to The Guardian, the minerals found are similar to Montmorillonite, which is formed here on Earth under the influence of neutral pH water, the same type of liquid that flows through our taps. This means that potentially this substance offers better conditions for the origin of life forms. The evidence of water found on Mars so far has always been much more acidic.
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According to the publication, as the planet was changing into the desert it is today, the process of water evaporation was becoming increasingly acidic due to the high concentration of minerals that remained in the remaining liquid. The evidence Opportunity found dates back to a time before this process, when frequent rainfall occurred on Mars and the environment there was more like Earth's.
This is not the first trace that “drinking” water has existed on the Red Planet in the past, as Curiosity found similar evidence in March this year during one of its missions in the Gale Crater.