A team of researchers from the University of Texas at Austin has conducted a groundbreaking study that maps ancient river basins on Mars, shedding light on the planet’s watery history. Published in the Proceedings of the National Academy of Sciences, this research aims to enhance our understanding of how much liquid water once existed on the Red Planet and to establish innovative techniques for mapping ancient river systems, both on Mars and potentially on other celestial bodies.
Using data from the Mars Orbiter Laser Altimeter (MOLA) and the Context Camera (CTX), the researchers meticulously examined Martian landscapes. MOLA was a vital instrument on NASA’s Mars Global Surveyor, which operated from 1997 to 2006, while CTX continues to provide comprehensive coverage of Mars aboard the Mars Reconnaissance Orbiter.
The study focused on identifying and mapping significant river systems, particularly those that exceed an area of 10,000 km², a standard for large drainage systems on Earth. Utilizing ArcGIS Pro, a mapping software well-regarded for both Earth and planetary analysis, the scientists identified 16 drainage systems. They estimate these systems generated approximately 28,000 km³ of sediment, which accounts for around 42 percent of the total sediment volume transported by flowing water across ancient Mars.
In addition to the river systems, the researchers discovered that outlet canyons contributed about 24 percent of the global river sediment volume on Mars.
Mars, believed to have formed approximately 4.5 billion years ago, has a complex history concerning its surface liquid water. While there is ongoing debate among scientists regarding the duration of liquid water’s presence, a 2022 study suggests that Mars may have had liquid water as recently as 2 billion years ago.
This recent mapping study highlights not only river basins but also other geomorphological features indicative of past water activity, such as deltas, outflow channels, gullies, and coastal-like terraces. Mineralogical evidence, including clays, sulfate minerals, carbonates, and hematite—often referred to as “blueberries” after being discovered by NASA’s Opportunity rover in 2004—further supports the existence of ancient water.
Several hypotheses exist regarding the loss of liquid water on Mars, including the planet’s diminishing magnetic field, climate changes, and geological burial. Unlike Earth, Mars has a smaller core, leading to a quicker cooling process and a faster decline in its magnetic field. This exposure to solar and cosmic radiation may have stripped away much of Mars’ water, with some potentially escaping into space while other water could have been trapped underground or at the poles.
As research continues, scientists eagerly anticipate further insights into the ancient river basins of Mars. The mapping of these drainage systems is a significant step in understanding the planet’s climate history and its potential for past life. The findings not only contribute to our knowledge of Mars but also pave the way for future exploration and study of other planets within our solar system.
The ongoing exploration of Mars serves as a reminder of the importance of scientific inquiry as we strive to unravel the secrets of the universe.
