Modern glacier remains found near Mars equator suggest water ice possibly present today at low latitudes

In a groundbreaking announcement on the 54th Lunar and Planetary Science Convention held in The Woodlands, Texas, scientists revealed the invention of a relict glacier close to the equator of Mars. Situated in Jap Noctis Labyrinthus at coordinates 7° 33′ S, 93° 14′ W, this discovering is important because it implies the presence of floor water ice on Mars in current instances, even close to the equator. This discovery raises the chance that ice should exist at shallow depths within the space, which might have vital implications for future human exploration.

The floor function recognized as a “relict glacier” is considered one of many light-toned deposits (LTDs) discovered within the area. Usually, LTDs consist primarily of light-colored sulfate salts, however this sediment additionally exhibits most of the options of a glacier, together with crevasse fields and moraine bands. The glacier is estimated to be 6 kilometers lengthy and as much as 4 kilometers extensive, with a floor elevation starting from +1.3 to +1.7 kilometers. This discovery means that Mars’ current historical past could have been extra watery than beforehand thought, which might have implications for understanding the planet’s habitability.

“What we have discovered is just not ice, however a salt deposit with the detailed morphologic options of a glacier. What we predict occurred right here is that salt fashioned on high of a glacier whereas preserving the form of the ice under, right down to particulars like crevasse fields and moraine bands,” stated Dr. Pascal Lee, a planetary scientist with the SETI Institute and the Mars Institute, and the lead creator of the examine.

The presence of volcanic supplies blanketing the area hints of how the sulfate salts might need fashioned and preserved a glacier’s imprint beneath. When freshly erupted pyroclastic supplies (mixtures of volcanic ash, pumice, and sizzling lava blocks) are available in contact with water ice, sulfate salts like those generally making up Mars’s light-toned deposits could type and construct up right into a hardened, crusty salt layer.

“This area of Mars has a historical past of volcanic exercise. And the place a number of the volcanic supplies got here involved with glacier ice, chemical reactions would have taken place on the boundary between the 2 to type a hardened layer of sulfate salts,” explains Sourabh Shubham, a graduate scholar on the College of Maryland’s Division of Geology, and a co-author of the examine. “That is the most definitely clarification for the hydrated and hydroxylated sulfates we observe on this light-toned deposit.”

Over time, with erosion eradicating the blanketing volcanic supplies, a crusty layer of sulfates mirroring the glacier ice beneath grew to become uncovered, which might clarify how a salt deposit is now seen, presenting options distinctive to glaciers reminiscent of crevasses and moraine bands.

“Glaciers usually current distinctive varieties of options, together with marginal, splaying, and tic-tac-toe crevasse fields, and in addition thrust moraine bands and foliation. We’re seeing analogous options on this light-toned deposit, in type, location, and scale. It is very intriguing,” stated John Schutt, a geologist on the Mars Institute, skilled icefield information within the Arctic and Antarctica, and a co-author of this examine.

The glacier’s fine-scale options, its related sulfate salts deposit, and the overlying volcanic supplies are all very sparsely cratered by impacts and have to be geologically younger, doubtless Amazonian in age, the newest geologic interval which incorporates trendy Mars. “We have identified about glacial exercise on Mars at many places, together with close to the equator within the extra distant previous. And we have identified about current glacial exercise on Mars, however to date, solely at increased latitudes. A comparatively younger relict glacier on this location tells us that Mars skilled floor ice in current instances, even close to the equator, which is new,” stated Lee.

It stays to be seen whether or not water ice would possibly nonetheless be preserved beneath the light-toned deposit or if it has disappeared totally. “Water ice is, at current, not steady on the very floor of Mars close to the equator at these elevations. So, it isn’t shocking that we’re not detecting any water ice on the floor. It’s attainable that each one the glacier’s water ice has sublimated away by now. However there’s additionally an opportunity that a few of it’d nonetheless be protected at shallow depth underneath the sulfate salts.”

The examine attracts an analogy with the traditional ice islands on salt lakebeds, or salars, of the Altiplano in South America. There, outdated glacier ice has remained shielded from melting, evaporation, and sublimation beneath blankets of shiny salts. Lee and his co-authors hypothesize an identical scenario to elucidate how sulfate salts on Mars would possibly find a way to protect in any other case sublimation-vulnerable ice at low latitudes on the planet.

If there’s nonetheless water ice preserved at shallow depths at a low latitude on Mars, there can be implications for science and human exploration. “The will to land people at a location the place they may be capable of extract water ice from the bottom has been pushing mission planners to think about increased latitude websites. However the latter environments are sometimes colder and tougher for people and robots. If there have been equatorial places the place ice may be discovered at shallow depth, then we would have the very best of each environments: hotter circumstances for human exploration and nonetheless entry to ice,” stated Lee.

However Lee cautions that extra work nonetheless must be accomplished: “We now have to find out if and the way a lot water ice would possibly really be current on this relict glacier, and whether or not different light-toned deposits may also have, or have had, ice-rich substrates.”