First evidence of wet-dry cycles on early Mars. Image Credit: NASA/JPL-Caltech/MSSS/IRAP.

First evidence of wet-dry cycles on early Mars

The cracks offer the first tangible evidence of wet-dry cycles, which on Earth are believed to have been essential in forming the complex chemical building blocks of life.


The discovery of a distinctive hexagonal pattern in ancient mud cracks on Mars offers tantalizing clues about the planet’s prehistoric climate. This intriguing discovery may hold the key to understanding the wet-dry cycles on Mars that could have led to the emergence of life. Could the Red Planet’s history provide insights into our own planet’s origins?

Mars Rover Uncovers Secrets of Ancient Mud Cracks

NASA’s Curiosity Mars rover has stumbled upon an exciting pattern of well-preserved ancient mud cracks. Scientists at France’s Institut de Recherche en Astrophysique et Planétologie, like William Rapin, are fascinated by these clues that might reveal Mars’ ancient climate.

The cracks offer the first tangible evidence of wet-dry cycles, which on Earth are believed to have been essential in forming the complex chemical building blocks of life.

A Closer Look at Mud Cracks and Their Significance

These mud cracks are found on Mount Sharp, within Gale Crater, where Curiosity is exploring the transitional zone between clay-rich and sulfate-rich layers. The T-shaped to Y-shaped junctions in the mud cracks, eventually forming a hexagonal pattern, indicate a history of repeated wet-dry conditions.


This pattern is not just a mere geological occurrence but a window into Mars’ ancient climate. The recurring exposures to water that formed these cracks represent a crucial phase when long dry spells began to dominate, and the waters in the crater started to wane.

Chemical Evidence and the Path to Life

The proximity of sulfate minerals, which form as water dries up, confirms a crust that made the mud cracks resistant to erosion. These preserved signs indicate Earth-like wet-dry cycles essential for molecular evolution leading to life.

A precise balance of water is crucial for life. While sustaining microbial life needs specific conditions, the promotion of chemical reactions leading to life requires another set. Wet-dry cycles control the concentration of chemicals vital for creating polymers, the long chains of carbon-based molecules considered as life’s building blocks.

Exploring Further with Curiosity’s Discoveries

For over 11 years, Curiosity has been unearthing evidence that ancient Mars could have supported microbial life. Now, it adds to its findings evidence that could explain the origins of life itself.

Unlike Earth, where tectonic activities erase prebiotic history, Mars’ surface is preserved, holding valuable insights into natural processes possibly leading to life. As Rapin pointed out, “It’s pretty lucky of us to have a planet like Mars nearby that still holds a memory of the natural processes which may have led to life.”


The discovery of the Pontours mud cracks by NASA’s Curiosity rover opens a fascinating chapter in our quest to understand Mars’ ancient wet-dry cycles and the origins of life. While there is much to be explored and understood, the Red Planet continues to reveal secrets that may answer profound questions about our very existence.

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Written by Ivan Petricevic

I've been writing passionately about ancient civilizations, history, alien life, and various other subjects for more than eight years. You may have seen me appear on Discovery Channel's What On Earth series, History Channel's Ancient Aliens, and Gaia's Ancient Civilizations among others.

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