Scientists have announced an important discovery of a relict glacier near the equator of Mars, during the 54th Lunar and Planetary Science Conference in Texas. The glacier is located in Eastern Noctis Labyrinthus and has significant implications for the preservation of water ice at low latitudes on Mars. Although it is not ice, but a salt deposit that formed on top of a glacier, the discovered ‘relict glacier’ demonstrates the presence of surface water ice on Mars in recent history, even close to the equator. This finding could have implications for understanding the planet’s habitability and could also contribute towards future human exploration.
Important Details about Equatorial Relict Glacier Uncovered on Mars –
– A relict glacier has been discovered near the equator of Mars in Eastern Noctis Labyrinthus, indicating the presence of surface water ice on Mars in recent history.
– This glacier is estimated to be 6 kilometers long and up to 4 kilometers wide, with a surface elevation ranging from +1.3 to +1.7 kilometers, and is one of many light-toned deposits found in the region.
– The surface feature identified as a “relict glacier” shows many of the features of a glacier, including crevasse fields and moraine bands, and is a significant indication of the potential existence of ice at shallow depths in the region.
– The presence of volcanic materials blanketing the region hints at how sulfate salts might have formed and preserved a glacier’s imprint underneath.
– The glacier’s fine-scale features, its associated sulfate salts deposit, and the overlying volcanic materials are all very sparsely cratered by impacts and must be geologically young, likely Amazonian in age, the latest geologic period which includes modern Mars.
– If there is still water ice preserved at shallow depths at a low latitude on Mars, there would be implications for scientific research and human exploration, as it could offer access to warmer conditions for human exploration and still access to ice.
– More work needs to be done to determine if, and how much, water ice might actually be present in this relict glacier, and whether other light-toned deposits might also have, or have had, ice-rich substrates.
A Relict Glacier near Mars’ Equator: Evidence for Recent Glaciation and Volcanism in Eastern Noctis Labyrinthus
During the 54th Lunar and Planetary Science Conference that was held in The Woodlands, Texas, scientists made a groundbreaking discovery of a relict glacier located near the equator of Mars. This glacier is located in Eastern Noctis Labyrinthus at coordinates 7° 33′ S, 93° 14′ W, and its discovery is a significant indication of the presence of surface water ice on Mars in recent history, even close to the equator.
Water ice plays a significant role in scientific research and human exploration, and the preservation of water ice at shallow depths and low latitudes on Mars has enormous implications for both. This finding suggests the potential existence of ice at shallow depths in the region, which could have crucial implications for future human exploration.
The discovery was of a surface feature identified as a “relict glacier,” which is one of many light-toned deposits (LTDs) found in the region. Typically, LTDs consist mainly of light-colored sulfate salts, but this deposit also shows many of the features of a glacier, including crevasse fields and moraine bands. The glacier is estimated to be 6 kilometers long and up to 4 kilometers wide, with a surface elevation ranging from +1.3 to +1.7 kilometers.
“What we’ve found is not ice, but a salt deposit with the detailed morphologic features of a glacier. What we think happened here is that salt formed on top of a glacier while preserving the shape of the ice below, down to details like crevasse fields and moraine bands,” said Dr. Pascal Lee, a planetary scientist with the SETI Institute and the Mars Institute, and the lead author of the study.
The presence of volcanic materials blanketing the region hints of how the sulfate salts might have formed and preserved a glacier’s imprint underneath. When freshly erupted pyroclastic materials come in contact with water ice, sulfate salts like the ones commonly making up Mars’ light-toned deposits may form and build up into a hardened, crusty salt layer.
This region of Mars has a history of volcanic activity, and where some of the volcanic materials came in contact with glacier ice, chemical reactions would have taken place at the boundary between the two to form a hardened layer of sulfate salts. This is the most likely explanation for the hydrated and hydroxylated sulfates observed in the light-toned deposit.
Over time, with erosion removing the blanketing volcanic materials, a crusty layer of sulfates mirroring the glacier ice underneath became exposed, which would explain how a salt deposit is now visible, presenting features unique to glaciers such as crevasses and moraine bands.
“Glaciers often present distinctive types of features, including marginal, splaying, and tic-tac-toe crevasse fields, and also thrust moraine bands and foliation. We are seeing analogous features in this light-toned deposit, in form, location, and scale. It’s very intriguing,” said John Schutt, a geologist at the Mars Institute.
The glacier’s fine-scale features, its associated sulfate salts deposit, and the overlying volcanic materials are all sparsely cratered by impacts and must be geologically young, likely Amazonian in age. “We’ve known about glacial activity on Mars at many locations, including near the equator in the distant past. And we’ve known about recent glacial activity on Mars, but so far, only at higher latitudes. A relatively young relict glacier in this location tells us that Mars experienced surface ice in recent times, even near the equator, which is new,” said Lee.
It remains to be seen whether water ice might still be preserved underneath the light-toned deposit or if it has disappeared entirely. “Water ice is, at present, not stable at the very surface of Mars near the equator at these elevations. So, it’s not surprising that we’re not detecting any water ice at the surface. It is possible that all the glacier’s water ice has sublimated away by now. But there’s also a chance that some of it might still be protected at shallow depth under the sulfate salts.”
The study draws an analogy with the ancient ice islands on salt lakebeds of the Altiplano in South America. There, old glacier ice has remained protected from melting, evaporation, and sublimation underneath blankets of bright salts. Lee and his co-authors hypothesize a similar situation to explain how sulfate salts on Mars might be able to offer protection to otherwise sublimation-vulnerable ice at low latitudes on the planet.
If there is still water ice preserved at shallow depths at a low latitude on Mars, there would be implications for science and human exploration. “The desire to land humans at a location where they might be able to extract water ice from the ground has been pushing mission planners to consider higher latitude sites. But the latter environments are typically colder and more challenging for humans and robots. If there were equatorial locations where ice might be found at shallow depth, then we’d have the best of both environments: warmer conditions for human exploration and still access to ice,” said Lee.
However, more work still needs to be done to determine if, and how much, water ice might actually be present in this relict glacier, and whether other light-toned deposits might also have, or have had, ice-rich substrates. This discovery presents a challenge as well as an opportunity for future exploration and understanding of one of the most intriguing planets of our solar system.