Researchers from the University of Texas at Austin have achieved a significant breakthrough in understanding Mars’ ancient hydrology by mapping the planet’s river basins for the first time. The study, published in the *Proceedings of the National Academy of Sciences*, aims to shed light on the amount of water that once existed on the Red Planet and how it shaped its landscape.
Utilizing data from the Mars Orbiter Laser Altimeter (MOLA) and the Context Camera (CTX), scientists meticulously identified and labeled Martian drainage systems. MOLA was a crucial instrument aboard NASA’s Mars Global Surveyor, which operated from 1997 to 2006, while CTX is currently in orbit around Mars on the Mars Reconnaissance Orbiter, providing comprehensive coverage of the planet’s surface.
The team focused on mapping drainage systems that exceeded 10,000 square kilometers, a baseline commonly used for large drainage systems on Earth. Their efforts led to the identification of 16 drainage systems, which they estimate collectively produced approximately 28,000 cubic kilometers of sediment. This volume is thought to account for about 42 percent of the total flowing sediment on ancient Mars.
In their findings, the researchers noted that outlet canyons alone contributed around 24 percent of the global river sediment amount on the planet. This research not only reveals the extent of ancient waterways but also offers new methodologies for studying similar features on Mars and other celestial bodies.
Mars is believed to have formed around 4.5 billion years ago, and while the scientific community debates the timeline of surface liquid water, a study from 2022 suggested that Mars may have had liquid water as recently as 2 billion years ago. The present study highlights various geomorphological features indicative of past water, including deltas, outflow channels, and coastal-like terraces.
Mineralogical evidence also supports these findings, with materials such as clays, sulfates, carbonates, and hematite—known as “blueberries”—discovered by NASA’s Opportunity rover in 2004. These minerals suggest a history of liquid water interacting with the Martian surface.
Several theories explain how Mars lost its liquid water. Scientists propose that the planet’s cooling core led to a diminished magnetic field, exposing its surface to solar and cosmic radiation. This exposure may have stripped Mars of its atmosphere and water, with some escaping into space while other water could have become buried, potentially stored in the planet’s polar regions.
As research continues, the scientific community eagerly anticipates what further insights will emerge about Mars’ river basins. Ongoing studies may reveal more about the planet’s history and the conditions that once allowed liquid water to exist. The findings from this study mark a significant step in understanding Mars’ hydrological past and its implications for future exploration.
