Can a new type of glacier on Mars aid future astronauts?

On April 21, 1908, close to Earth’s North Pole, the Arctic explorer Frederick Albert Cook dinner scrawled in his diary a memorable phrase: “We have been the one pulsating creatures in a useless world of ice.” These phrases could quickly take on new significance for humankind in one other useless world of hidden ice, submerged beneath the purple sand of its frigid deserts. This useless world is Mars, and the desert is the planet’s mid-latitude area generally known as Arcadia Planitia.

Sharon Hibbard is a Ph.D. candidate in geology and planetary science on the College of Western Ontario and the lead writer of a new scientific paper on glaciers and glacier-like exercise in Arcadia Planitia, just lately printed in Icarus. Hibbard and associates have recognized proof of a glacier on this area that defies expectations and, attributable to its distinctive traits, might function a water supply for future human landings and exploration.

Proof of Martian glaciers, referred to extra cautiously by the scientific group as “viscous circulation options”, have been first investigated within the Nineteen Seventies utilizing satellite tv for pc imagery from NASA’s Viking program, the second and third spacecraft to achieve the floor of Mars. Scientists have been intrigued by widespread ripples and flows within the Martian floor, many with moraine-like options that bore putting resemblance to the glacial landscapes of Earth.

The new examine investigates viscous circulation options within the decrease mid-latitudes of Arcadia Planitia, exhaustively mapping dozens of floor options possible produced by Mars’ subterranean glaciers made of water ice. Within the course of of mapping, the crew discovered one thing reasonably surprising: proof of ice circulation in a giant, flat plain. This type of ice circulation is just not generally seen on Mars, the place most of the outstanding ice-related options take the shape of ripples and furrows in valleys and on hillsides the place gravity can immediate ice to circulation downhill. Hibbard’s crew discovered these “sinuous options” in a flat-lying area of Arcadia Planitia, mysteriously remoted from any bluffs or slopes. How might this ice within the plains of Arcadia Planitia probably be flowing?

Inspecting the presence of water on Mars

Knowledgeable guesses in regards to the existence of water and ice on Mars preceded the period of spaceflight by tons of of years. Telescopic remark of Mars’ larger landforms and polar ice caps led astronomer William Herschel to speculate in 1784 that the purple planet was populated by clever life.

Advances in telescope expertise had largely dispelled this principle by the twentieth century, however the existence of water and water ice on Mars remained unsure till the primary orbiters and landers arrived within the Nineteen Seventies. Not solely did NASA’s Viking program uncover hint quantities of atmospheric water vapor, however its orbital imagery additionally revealed the existence of quite a few glacier-like options. Uncovered water ice sublimates away within the low pressures and freezing temperatures current on the floor of Mars, so if water ice glaciers have been answerable for the noticed Earth-like flows, researchers conjectured that the ice should be protected by a thick layer of particles. Additional observations confirmed this speculation, and in ensuing a long time the scientific group proceeded to map, catalog and categorize many 1000’s of glacier candidates with various levels of confidence. Over time, our capabilities grew from hypothesis in telescope eyepieces to express, on-site observations throughout the electromagnetic spectrum.

The presence of water ice beneath the floor of Mars was confirmed in 2008 by the Phoenix lander, reinforcing the findings of Mars Odyssey, whose sensors indicated huge quantities of subsurface water ice on the extra temperate mid-latitudes in 2002. For instance, the subterranean water ice of the flat Arcadian plains was instantly measured by Mars Reconnaissance Orbiter’s radar and located to start 6 centimeters beneath the floor layer of mud and particles, and lengthen downward to a median depth of 38 meters.

Understanding the surprising ice circulation

Seeing to the underside of an ice sheet to discern what makes it circulation is not any straightforward process, and solely grows extra complicated when the ice sheet is 170 million miles away. Luckily, the mysterious circulation options Hibbard’s crew discovered within the flat Arcadian plains should not distinctive on this photo voltaic system—actually, we’d like not journey far in any respect to check an analog. Hibbard and associates recognized exceptional similarities to Antarctica‘s ice streams, areas in its flat ice sheets the place a sure quantity of ice strikes extra quickly than its environment.

Whereas up to date science nonetheless lacks a detailed understanding of what causes these ice streams on Earth, researchers have inferred that subsurface topography and melting on the backside of the ice sheet could each play a function. Hibbard notes that the Arcadian flows exhibit a number of of the important thing options of Earth’s ice streams. The Arcadian ice has since stopped flowing, accumulating a thicker layer of floor particles, turning into a stagnant ice stream.

“Discovering attainable circulation options on this flat-lying area was very thrilling” stated Hibbard in an interview with GlacierHub. “Earlier research have prompt there may be a buried ice sheet at our examine website, and our proof of channelized ice inside this ice sheet signifies that there are extra complicated glacial dynamics at hand on Mars.”

Implications for human exploration

These distinctive traits of the Arcadian plains ice sheet elevate one other query, one which William Herschel actually would have liked to listen to: might the water ice be extracted and utilized by human astronauts?

Whereas most Martian glaciers and their subsurface ice lie close to bluffs and on slopes, this ice sits close to the floor and types a temperate, flat ice sheet coated with few boulders or different geographical hazards. It will make for a perfect touchdown website. Hibbard proposes that this area is “favorable for future in situ useful resource utilization and human missions,” because of the sheer quantity and cheap purity of the near-surface ice.

Nilton Renno, an astrobiologist on the College of Michigan emphasizes the problem of water ice extraction on Mars, writing to GlacierHub that “[many] glaciers are in areas more difficult for human exploration as a result of of the decrease temperatures throughout the winter and topography,” although “in excessive latitudes, the water ice is definitely accessible.” The Phoenix Lander simply uncovered subsurface water ice at excessive northern Martian latitudes, an space people are unlikely to go to attributable to its excessive chilly and lack of daylight.

Germán Martínez, a workers scientist on the Lunar and Planetary Institute in Houston, affirms the feasibility of the mid-latitude Arcadia Planitia as a touchdown website, writing to GlacerHub that “on the whole, it’s extra possible to go to low and mid latitudes, the place temperatures are milder and photo voltaic power is accessible all year long … in these mid and low latitudes, although, water ice is often deeper within the subsurface than in polar latitudes.”

The shallow ice discovered by Hibbard and associates stands other than this development, solely barely buried and way more simply accessible than different water ice deposits usually discovered at mid-Martian latitudes. In time, the frozen water in Arcadia Planitia may even see the floor as soon as extra, discovering use by the hands of future astronauts, reworking the useless floor of an icy world into one with a little extra life.

Supply:Shannon M. Hibbard et al. Proof for widespread glaciation in Arcadia Planitia, Mars, Icarus (2021). DOI: 10.1016/j.icarus.2020.114298

Can a new type of glacier on Mars aid future astronauts?

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