Scientists recommend eight potential Martian caves as high-priority sites in the hunt for ancient alien life.

Pits and channels of Hebrus Valles, Mars.

NASA / JPL-Caltech / Univ. of Arizona

A team of scientists from Shenzhen University in China has discovered the first evidence of a new type of cave on the Red Planet. The researchers claim these may have once provided the conditions required for harboring alien life.

These underground caverns were likely formed by water dissolving rock—a type of rock formation known as a karstic cave on Earth.

The team behind the discovery claims that future missions to the Red Planet should target these underground caverns. They could find traces of ancient life that once resided in the watery caves, whilst using them as a shelter and exploration base.

Identifying Martian cave systems

For years, scientists have been searching for signs of ancient life on Mars. One possible target to help narrow the search parameters is cave systems. These rock formations would provide shelter from severe dust storms, high radiation, and extreme temperatures on the surface of the Red Planet.

Chenyu Ding at Shenzhen University in China, and colleagues, focused on eight potential cave sites, called skylights, for their study. These sites are located in the Hebrus Valles, on Mars’ northern hemisphere. They are comprised of eight pits that were mapped by previous Mars missions.

The team detailed their findings in a paper published in The Astrophysical Journal Letters. To date, the majority of Martian caves discovered have been lava tubes, indicating that they were formed by volcanic activity. In this case, however, the researchers have provided evidence strongly suggesting these caves were carved by water.

A conceptual model illustrating Karstic cave formation on Mars. Source: The Astrophysical Journal Letters

Using data from the Thermal Emission Spectrometer (TES) onboard NASA’s Mars Global Surveyor, researchers found that the rocks around these locations are rich in carbonates and sulfates. These are the types of rocks that water easily dissolves. The team also created 3D structural models using high-resolution imagery. This indicates that the shapes of these formations are consistent with those caused by water collapse.

Earth-like Martian caves could harbor alien life

The team claims the cave-forming process likely resembled that of karstic cave formations on Earth. On our planet, these caves typically form when water dissolves soluble rock. Also known as solution caves, these originate from large underground cracks that are widened by water, eventually forming cave systems.

In their paper, the researchers explained that the skylights “are interpreted as the first known potential karstic caves on Mars, representing collapse entrances formed through the dissolution of water-soluble lithologies—defining a new cave-forming class distinct from all previously reported volcanic and tectonic skylights.”

The scientists behind the study believe the eight karstic caves they identified should be marked as high-priority targets for future human or robotic missions to Mars. They provide two reasons. Firstly, these natural shelters could yield signs of ancient Martian life.

NASA’s Perseverance rover is searching for alien life on the Jezero crater because it was once an ancient lakebed fed by flowing water. By the very nature of their formation, these caves would have had similar watery conditions. Secondly, even if life was not discovered in the caves, they could provide stable habitats for future astronauts exploring the Red Planet.

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Chris Young is a journalist, copywriter, blogger and tech geek at heart who’s reported on the likes of the Mobile World Congress, written for Lifehack, The Culture Trip, Flydoscope and some of the world’s biggest tech companies, including NEC and Thales, about robots, satellites and other world-changing innovations.