Water on Mars—A Literature Review

Abstract

To assess Mars’ potential for both harboring life and providing useable resources for future human exploration, it is of paramount importance to comprehend the water situation on the planet. Therefore, studies have been conducted to determine any evidence of past or present water existence on Mars. While the presence of abundant water on Mars very early in its history is widely accepted, on its modern form, only a fraction of this water can be found, as either ice or locked into the structure of Mars’ plentiful water-rich materials. Water on the planet is evaluated through various evidence such as rocks and minerals, Martian achondrites, low volume transient briny outflows (e.g., dune flows, reactivated gullies, slope streaks, etc.), diurnal shallow soil moisture (e.g., measurements by Curiosity and Phoenix Lander), geomorphic representation (possibly from lakes and river valleys), and groundwater, along with further evidence obtained by probe and rover discoveries. One of the most significant lines of evidence is for an ancient streambed in Gale Crater, implying ancient amounts of “vigorous” water on Mars. Long ago, hospitable conditions for microbial life existed on the surface of Mars, as it was likely periodically wet. However, its current dry surface makes it almost impossible as an appropriate environment for living organisms; therefore, scientists have recognized the planet’s subsurface environments as the best potential locations for exploring life on Mars. As a result, modern research has aimed towards discovering underground water, leading to the discovery of a large amount of underground ice in 2016 by NASA, and a subglacial lake in 2018 by Italian scientists. Nevertheless, the presence of life in Mars’ history is still an open question. In this unifying context, the current review summarizes results from a wide variety of studies and reports related to the history of water on Mars, as well as any related discussions on the possibility of living organism existence on the planet.

Volcanic Holocrystalline Bedrock and Hydrothermal Alteration: A Terrestrial Analogue for Mars

“…Although our experimental setup favor the hydrothermal alteration as responsible for the formation of the smectite clay, also the role of chemical weathering also suggested in different regions on Mars cannot be excluded (e.g., [8,16,17,81,83]). Several studies proposed geomorphological evidence based on numerous and well-preserved valley networks and channels, and many impact craters that show deltas, lakes and sedimentary layers (e.g., [81,84,85]), coupled with a hydrated mineralogy, which suggest an ancient water-rock interaction (e.g., [8]), which may have contributed to the neogenesis of smectite under environmental meteoric conditions. Specifically, the chemical weathering processes in the Gale and Gusev craters on Mars where the alkaline basalts outcrop, induced the formation of smectite in analogies with the Etna basaltic sample (see Section 3.1) Although our experimental setup favor the hydrothermal alteration as responsible for the formation of the smectite clay, also the role of chemical weathering also suggested in different regions on Mars cannot be excluded (e.g., [8,16,17,81,83]).…”

Microbial diversity and activity in Southern California salterns and bitterns: analogues for remnant ocean worlds

“…Specifically, evaporative brine systems (e.g. salterns and naturally occurring salt lakes) serve as terrestrial analogues of Mars's ancient receding oceans, which could have been among the last refugia of life as the planet transitioned from wet to dry (Tosca et al ., 2008; Altheide et al ., 2009; Nazari‐Sharabian et al ., 2020). Because these environments may have a high potential for biosignature preservation, they are prime habitats for life detection missions that can be guided by advanced knowledge of halophile ecology and physiology (Fredrickson et al ., 1997; Fernández‐Remolar et al ., 2013).…”

Delta Deposits on Mars: A Global Perspective

“…River deltas are landforms generated by deposition of fluid-carried sediments as the flow enters a slower-moving or stagnant water body. The presence of delta deposits on Mars has been thoroughly demonstrated for decades (e.g., Di Achille & Hynek, 2010;Nazari-Sharabian et al, 2020;Ori et al, 2000). Large scale mapping (Di Achille & Hynek, 2010;Di Biase et al, 2013;Hauber et al, 2013;Wilson et al, 2021) highlighted the presence of several delta fans mainly located at the dichotomy boundary.…”