December 9, 2023

Possible discovery of an ancient glacier on Mars

Scientists at the Seti Institute said that there is evidence of an ancient glacier on Mars, in the eastern part of the so-called Noctis Labyrinthus (“Labyrinth of the Night”, in a free translation). One A report on the results of the study It was presented during the 54th Lunar and Planetary Science Conference, which took place from March 13-17 this year.

The researchers did not find water ice, “common ice,” in the sediments, but they did find hydrated, hydrogenated sulfates. These salts may have formed as a result of the interaction of volcanic ash, or lava deposits, with glacial ice in the past.

“This region of Mars has a history of volcanic activity,” explains Sarab Shubham, co-author of the study. “Where some of the volcanic material came into contact with the glacial ice, chemical reactions were taking place at the boundary between the two, forming a solid layer of sulfate salts. This is the most likely explanation for the hydrated, hydroxylated sulfates we observed in this pale-colored sediment.”

“What we found is not ice, but salt deposits with the detailed morphological characteristics of a glacier,” said Pascal Lee, the team leader. For the discovery, the researchers analyzed data from the High Resolution Imaging Science Experiment (HiRISE) on NASA’s Mars Reconnaissance Orbiter (MRO).

About the glacier on Mars

The glacier is located 160 kilometers (km) northwest of Odeman crater and is about 2 to 4 km wide and 6 km long. Its shape is composed of light sediments, which exhibit linear and “arc-shaped” structure. There are also concentric and wedge-shaped folds and fracture patterns.

Regarding the formation of glaciers, Lee said researchers believe that “salt forms on top of a glacier, and maintains the shape of the ice underneath, down to details such as fault fields and moraine groups.”

“We know about recent glacial activity on Mars, but so far only at high latitudes,” he added. “A relatively small glacier at this location tells us that Mars has had surface ice recently, even near the equator, which is novel.”

The glacier lost all or most of its ice reserves over time, but salt deposits remained, thus maintaining the basic shape of the glacier. It is likely that some amount of ice remains in the glacier, isolated from the external environment by sediments.