Recent work has identified more than 17,000 km of ancient rivers on a plain of Mars called Arabia Terra . In this study, carried out by scientists from University College London and the Open University of the United Kingdom and published in the scientific journal Geology, more than a thousand high-resolution images (6 meters per pixel) from the NASA Mars orbiter have been examined. Reconnaissance, which have revealed the existence of previously unobserved channels and valleys in this region. Their results add to the multiple evidences that seem to indicate that in the past, the planet’s temperature was high enough for liquid water to flow across its surface, modeling the landscape.
Climate models made in this area had already predicted rain in Arabia Terra but until now there was no geological evidence, so many scientists considered Mars to be an icy planet covered by glaciers. “The observation of these river systems supports that idea and suggests that the planet was once hot and humid, a much more favorable environment for life,” explains Joel Davis, lead author of the study.
The structures observed by this study are called “inverted channels” and are made up of sand and gravel. These materials are deposited on the bottom of the rivers when they are active. As the river gradually dries up, the material around it erodes while the channels remain as positive landforms. In the case of the Arabia Terra canals, these structures are approximately 30 meters high and up to 2 km wide.
These structures are not exclusive to Mars, on Earth they can also be observed in desert environments such as Oman, Egypt or Utah, although in most cases erosion takes away these structures before they can be considered. inverted channels.
The work concludes that Arabia Terra could have been a gigantic floodplain on the border with the highlands and its humid and warm climate could have supported life , therefore it is of great scientific interest. “In fact, one of the sites considered for the mission of the European Space Agency ExoMars Rover that will be sent to the red planet in 2020, is one of these inverted channels, Aram Dorsum”, comments Dr. Matthew Balme, professor at the Open University and co-author of the study.
The next step for these researchers will be to study these inverted channels in great detail, using high-resolution images from NASA’s Mars Reconnaissance Orbiter camera.
