Scientists Reveal Evidence of Massive Ancient Ocean on Mars

Researchers have uncovered compelling evidence suggesting that Mars once hosted a vast ocean capable of supporting life. An international team, utilizing advanced satellite data, simulated sea levels in the **Coprates Chasma**, a significant feature of the **Valles Marineris**, the largest canyon in the solar system. Their findings, published in the journal **NPJ Space Exploration**, indicate that ancient river deltas on Mars resemble those found on Earth, reinforcing the idea that the planet was once a “blue planet” approximately **three billion years ago**.

The team analyzed satellite imagery from the **European Space Agency’s ExoMars Trace Gas Orbiter**, **Mars Express**, and **NASA’s Mars Reconnaissance Orbiter**. They observed geomorphologic structures in the Valles Marineris that closely mimic the mouths of rivers flowing into oceans on Earth. This led them to infer a historical sea level, indicating the period when the planet had its highest availability of surface water.

Ignatius Argadestya, a PhD student from the **University of Bern**, expressed his excitement over the findings, stating, “The unique high-resolution satellite images of Mars have enabled us to study the Martian landscape in great detail by surveying and mapping.” He highlighted the remarkable similarities between Martian features and Earth’s mountainous landscapes. “I was particularly impressed by the deltas that I discovered at the edge of one of the mountains,” he added.

As the team compared Martian “fan deltas” with those on Earth, they found striking correspondences. According to coauthor and geology professor **Fritz Schlunegger**, the evidence suggests that these structures represent the mouths of rivers flowing into a substantial ocean. They estimated that the ocean could have been at least the size of the **Arctic Ocean**.

While Schlunegger acknowledged that previous research has posited the existence of such an ocean, their study provides new insights based on high-resolution imagery and detailed reconstruction of ancient coastlines. Argadestya noted, “With our study, we were able to provide evidence for the deepest and largest former ocean on Mars to date — an ocean that stretched across the northern hemisphere of the planet.”

The implications of these findings for the search for ancient life on Mars are still being explored. Nonetheless, they offer an intriguing perspective on the planet’s history, suggesting a time when it was a vibrant, water-rich environment.

As scientists continue to analyze the Martian landscape, this research presents a tantalizing glimpse into the potential for ancient life on a planet that is now a stark desert, far removed from its once-thriving past.