Could It Have Rained on Ancient Mars? New Study Supports a Wetter, Warmer Past

According to the news of ankarahaberler.com,, planetary scientists may finally be closer to solving one of the great Martian mysteries: Was ancient Mars cold and dry, or did it go through a warm, rainy period? A new study by a team of geologists from the University of Colorado Boulder sheds light on this question with groundbreaking simulations suggesting that early Mars might have experienced precipitation, flowing rivers, and long-lived lakes.

Traces of Water Across Mars’ Ancient Landscape

During what scientists call the Noachian era—approximately 4.1 to 3.7 billion years ago—Mars seems to have been home to vast river valleys and interconnected lake systems. These geological features, especially around the Martian equator, suggest that water once played a powerful role in shaping the surface of the Red Planet. Valleys that descend from higher altitudes to lower plains, with branching tributaries, resemble terrestrial river systems that are formed by continuous precipitation and surface runoff.

This naturally raises a critical question: Where did all that water come from? There are two primary theories. The first suggests Mars never experienced significant warming. According to this view, surface water formed only when ice sheets melted during brief periods of climatic fluctuation—perhaps triggered by volcanic activity or asteroid impacts.

The second, more daring hypothesis argues that Mars actually experienced rain and snow, allowing for the formation of semi-permanent or even seasonal rivers and lakes.

Simulations Favor the Rain Theory

 To test these two ideas, the researchers conducted extensive computer simulations. They adapted software typically used for studying Earth’s landscapes and applied it to simulated Martian terrain. Over tens of thousands of simulated years, the team tracked how water would interact with the Martian surface under both the ice-melt and the rainfall scenarios.

The results? Rain wins—and not by a little. The valleys and networks formed in the rainfall simulations matched existing Martian topography far more accurately than the ones produced by ice melt.

Most notably, the starting points of many Martian valleys appear at widely varying elevations. This distribution makes little sense if they were created solely by ice melting at specific altitudes. However, if rainfall occurred across broad regions, such valley patterns are entirely plausible.

How Did Mars Get Warm Enough?

 Here’s the catch: the early Sun was 25% dimmer than it is today, meaning Mars should have been too cold to support rain, even with a thicker atmosphere. So how could it have gotten warm enough?

This remains a hot topic (pun intended) in planetary science. Some researchers speculate that ancient Mars had a dense carbon dioxide-rich atmosphere, possibly with methane or hydrogen as secondary greenhouse gases. This could have created a transient greenhouse effect, enough to periodically thaw the surface and even trigger weather systems.

Others suggest massive volcanic eruptions or asteroid strikes could have temporarily altered the climate, allowing for brief but intense warm periods.

Real Terrain, Virtual Rain

 The University of Colorado team ran their simulations using digital elevation maps of real Martian terrain. They introduced both rain and snowfall into the simulations and analyzed how these conditions would carve valleys over millennia.

What they found was astonishing: the simulated river systems closely resembled those found on Mars today, especially in regions like the Margaritifer Terra and Arabia Terra, where ancient water erosion has long been suspected.

The models included erosion patterns, sediment transport, and hydrological feedbacks, creating what the researchers call a “plausible paleo-hydrological model” for ancient Mars.

A More Dynamic and Habitable Mars?

If the results hold up under peer review and further exploration, it could radically reshape our understanding of Mars. Rather than being a frozen wasteland since its birth, Mars may have enjoyed long stretches of temperate, wetter climate—perhaps even resembling a colder version of early Earth.

This opens the door to profound implications: If liquid water flowed and pooled on the surface for extended periods, could life have emerged there? And if so, is it possible remnants of that life might still be buried beneath the surface?

NASA, ESA and Future Missions

The study comes at a crucial time. NASA’s Perseverance rover and ESA’s upcoming Rosalind Franklin rover are both searching for biosignatures—clues that life may have existed on Mars. Knowing that rainfall and flowing water once shaped the Martian landscape boosts the odds that signs of ancient life could still be preserved in clay-rich sediments.

Moreover, the results could help future missions target specific areas where rain-fed river systems once existed, improving our chances of finding key geological samples.

Source: According to the news of ankarahaberler.com; Research published by the University of Colorado Boulder shows that rain and surface runoff are among the strong possibilities in the past of Mars.