A newly released image from the European Space Agency (ESA) shows an unusual “smiley face” shape on the surface of Mars, which could be a sign of ancient life on the Red Planet. The structure is actually a remnant of an ancient lake that dried up billions of years ago and is made up of chloride salt deposits.
The image was taken by ESA’s ExoMars Trace Gas Orbiter, which has been analyzing the levels of methane and other gases in Mars’ atmosphere since 2016. Normally, similar deposits would be indistinguishable from the rest of Mars’ surface, but when viewed using infrared cameras, they appear pink or violet.
The “smiley face” is part of a larger study published in the journal Scientific Data, which identified 965 different chloride salt deposits scattered across the Martian surface. These deposits are significant because they can provide optimal conditions for biological activity and preservation, making them a prime target for astrobiological exploration.
Mars was once a watery world with lakes, rivers, and a shallow ocean similar to those on Earth. However, somewhere between 2 billion and 3 billion years ago, the water dried up due to severe climate change, likely driven by the loss of Mars’ magnetic field. The salty deposits were left behind as the last water disappeared from Mars’ lakes.
The researchers believe that these deposits could have acted as a preservative, potentially keeping evidence of extinct lifeforms intact for billions of years. This discovery has implications for the search for signs of ancient life on Mars and highlights the importance of searching for biological activity in Martian salt deposits.
Source: https://www.space.com/scientists-spot-ancient-smiley-face-on-mars-could-contain-signs-of-life