Life on Mars? Researchers find ancient traces of a large ocean on the Red Planet.
A recently released series of topographic maps may put that question to rest as it provides fresh evidence that Mars once had the North Sea.

The most compelling evidence
According to a Penn State University press release, the maps provide the strongest evidence yet that the planet’s current hard, frozen surface was not what it once was and that sea levels rose during a long period of warm, humid weather. Increased.
Benjamin Cardenas, assistant professor of geosciences at Penn State and lead author of the study, explained that there had been a long and ongoing debate in the scientific community about whether there was an ocean in Mars’ low-elevation northern hemisphere.
Using topographical data, the research team was able to provide evidence of a 3.5-billion-year-old coastline spanning hundreds of thousands of square kilometers, with a sedimentary buildup at least 900 meters thick.
The researchers mapped data from NASA and the Mars Orbiter laser altimeter using software developed by the United States Geological Survey.
They traced about 6,500 kilometers of fluvial ridges and organized them into 20 systems to show that these ridges may be the remnants of an ancient Martian coastline that eroded into a river delta or submarine channel belt.
The team was capable of recognizing the evolution of the area’s paleogeography by using factors of rock formation, such as the thickness, height, position, and direction of possible sediment flow of ridge systems.
Cárdenas noted that this region, once an ocean, now known as Aulis Dorsa, has the densest concentration on Mars.
Proof of life
Cárdenas emphasized that stratigraphic records of Earth’s changing temperatures and life can be found in old sedimentary basins. If researchers want to look for evidence of life on Mars, the ocean that last covered Aeolis Dorsa would be the most sensible place to start, he said.

It’s a huge body of water, filled with sediment from the highlands, probably. It carries nutrients. It’s here, slowly bringing water in and out. This is exactly the kind of area in which historical Martian lifestyles should have evolved.
Cardenas and his colleagues have identified what they believe to be additional prehistoric rivers on Mars. According to a study published in the Journal of Sedimentary Research, the Curiosity rover encountered sedimentary strata on several outcrops from old river bars.
Different research published in Nature Geoscience examines a similar basin erosion model on Mars that uses acoustic imaging technology to visualize the stratigraphy beneath the Gulf of Mexico seafloor.
The scientists concluded that the fluvial ridges found on Mars are likely to be old river deposits that have been eroded by large basins such as Aeolis Dorsa.