Image of Mars from March 11, 2023. Photo: NASA
The structure of a glacier was located in the equatorial region of Mars, a relevant finding that implies the recent presence of water surface on Mars.
This discovery, located in the eastern Noctis Labyrinthus at coordinates 7° 33′ S, 93° 14′ W, raises the possibility that shallow ice may still exist in the area, which could have significant implications for future exploration. human.
The finding was presented at the 54th Lunar and Planetary Science Conference celebrada en The Woodlands, Texas
The surface feature was identified as a “leaving the glacier”. In geology, the term relict refers to structures or minerals from a parent rock that did not undergo metamorphic changes when the surrounding rock did, or to rocks that survived a destructive geological process.
This relict glacier is one of many light-toned deposits (LTD) found in the region. LTDs typically consist primarily of light colored sulfate saltsbut this deposit also shows many of the features of a glacier, including rift fields and moraine bands.
It is estimated that the glacier is 6 kilometers long and up to 4 kilometers wide, with a surface elevation ranging from +1.3 to +1.7 kilometers. This discovery suggests that the recent history of Mars may have been more watery than previously thought, which could have implications for understanding the planet’s habitability.
salt deposit
“What we have found is not ice, but a salt deposit with the detailed morphological characteristics of a glacier. What we think happened here is that salt formed on top of a glacier while retaining the shape of the ice below, down to details like crack fields and moraine bands,” Dr. Pascal Lee, a scientist, said in a statement. planetarium of the Mars Institute and the SETI Institute, and the lead author of the study.
The presence of volcanic materials covering the region suggests how sulfate salts might have formed and preserved the footprint of a glacier below. When newly erupted pyroclastic materials (mixtures of volcanic ash, pumice, and blocks of hot lava) come into contact with water ice, sulfate salts like those commonly forming light-hued deposits on Mars can form and accumulate in a crusty, hardened layer of salt.
“This region Mars has a history of volcanic activity. And when some of the volcanic material came into contact with the glacier ice, chemical reactions would have taken place at the boundary between the two to form a hardened layer of sulfate salts,” he explains. Saurabh Shubham, graduate student in the Department of Science at the University of Maryland. Geology, and co-author of the study. “This is the most likely explanation for the hydrated and hydroxylated sulfates we observed in this light-toned deposit.”
Over time, with the erosion that removed volcanic materials that covered it, a layer of sulphates was exposed that reflected the ice of the glacier below, which would explain why a salt deposit is now visible, which presents unique characteristics of glaciers, such as cracks and moraine bands.
“Glaciers often exhibit distinctive types of features, including fringe, spreading, and tic-tac-toe fields, as well as moraine bands and foliation. We are seeing analogous features in this light-toned deposit, in shape, location, and scale. It’s very intriguing,” said John Rubblea geologist at the Mars Institute, expert guide to ice fields in the Arctic and Antarctic, and co-author of this study.
Surface ice in recent times
The fine-scale features of the glacier, its associated sulfate salt deposit, and overlying volcanic materials have very few impact craters and they must be geologically young, probably of Amazonian age, the last geologic period that includes modern Mars. “We have known about glacial activity on Mars in many places, including near the equator in the more distant past. And we know about recent glacial activity on Mars, but so far, only at higher latitudes. A relatively young relict glacier on this place tells us that Mars experienced surface ice in recent timeseven near the equator, which is new,” Lee said.
It remains to be seen if the water ice is still preserved under the light-hued deposit or if it has disappeared entirely. “Water ice, at present, is not stable on the very surface of Mars near the equator at these elevations. So it is not surprising that we are not detecting any water ice on the surface. All the water ice on the glacier may have already sublimated.. But there is also the possibility that part of it is still protected at a shallow depth under the sulfate salts.”
The study establishes a analogy with ancient islands of ice in salt lake bedsor salt flats, of the Altiplano in South America. There, the ancient glacial ice has remained protected from melting, evaporation and sublimation under layers of glowing salts. Lee and his co-authors hypothesize a similar situation to explain how sulfate salts on Mars might offer protection to ice vulnerable to sublimation at low latitudes on the planet.