Recent findings from NASA's Curiosity rover indicate that ancient lakes on Mars were not covered by ice, challenging previous assumptions about the planet's climatic history. The study, published on January 15, 2025, in Science Advances, reveals evidence of wind-driven ripples in rock formations within Gale crater, dating back approximately 3.7 billion years.
The research team, comprising scientists from the U.S., U.K., and France, analyzed layers in the Martian rocks, concluding that some lakes must have existed in an ice-free state. The Curiosity rover, operational since 2012, has been instrumental in uncovering these geological features.
Two distinct sets of ripples were discovered: the first at the Prow rock outcrop, associated with ancient sand dunes, and the second at the nearby Amapari Marker Band. The ripples are small, measuring about 6 millimeters in height and spaced 4 to 5 centimeters apart, suggesting the lakes were shallow, less than 2 meters deep.
Lead author Claire Mondro from Caltech emphasized that this evidence extends the timeline for the presence of liquid water on Mars, hinting at the potential for microbial life during its history. The findings suggest that conditions on Mars were warm enough to sustain liquid water without ice coverage, providing valuable insights into the planet's paleoclimate.
John Grotzinger, a former project scientist for Curiosity, remarked on the significance of this discovery, stating that it advances the understanding of Mars' climatic evolution. The confirmation of ancient, ice-free lakes opens new avenues for exploration and research into the planet's capacity to support life.