More than 3 billion years ago, Mars was a vastly different world, characterized by the presence of liquid water that intermittently flowed across its surface. This past environment has fascinated scientists, as understanding Mars’ hydrological history is crucial for learning about its potential for past life and for planning future exploration missions. However, as Mars’ atmosphere thinned over time, the conditions necessary for liquid water to exist on the surface were lost. This dramatic atmospheric loss raises essential questions about the fate of the water that may have once played a vibrant role in its geological and possibly biological history.
In the past week, Bruce Jakosky, a Senior Research Scientist at the Laboratory for Atmospheric and Space Physics (LASP), has made headlines by challenging a recently published study in the Proceedings of the National Academy of Sciences (PNAS). In an incisive letter to the editor, Jakosky scrutinized the conclusions drawn from a 2024 study, which posited that Mars retains a substantial quantity of liquid water within its mid-crust. Jakosky pointed out that while this is an interesting hypothesis, it is neither the sole explanation nor the most substantiated by existing data, which suggests that a saturated crust is not a necessary condition.
Jakosky’s reexamination of the data utilized by this research team, which is primarily based on data collected during the NASA InSight mission, has significant ramifications for our understanding of Mars’ geological makeup. The InSight mission, launched in 2018, was designed to delve deep into Mars’ interior, using a lander equipped with advanced geophysical instruments. Its endeavor was to gather vital information about the planet’s seismic activity, heat flow, and crustal composition, even though the mission concluded in 2022 due to environmental hindrances caused by a Martian dust storm.
To evaluate the potential existence of liquid water in the Martian mid-crust, Jakosky’s analysis focused on various factors, including the arrangement of pore spaces within Martian rocks and how solid ice might coexist with varying degrees of saturation in the crust. He concluded that although the InSight data do not categorically negate the possibility of water being present, they also do not provide convincing support for the assertion that the mid-crust is saturated with water as suggested in the recent study.
The study conducted by geophysicist Vashan Wright from the Scripps Institution of Oceanography and colleagues put forth intriguing models that involved rock physics characteristics based on seismic and gravity data from the InSight mission. They speculated that a mid-crust composed of fractured igneous rocks filled with liquid water would offer a plausible explanation for the seismic waves recorded during the mission. The study estimated that if this water were dispersed evenly, it could form a global equivalent layer measuring between one to two kilometers deep, contrasting with Earth’s global equivalent layer of 3.6 kilometers, predominantly due to oceanic water.
However, Jakosky’s insights suggest that the findings of Wright and his team do not necessarily reflect the entire picture. He emphasizes that the InSight data merely allow for the possibility of some form of water—be it in liquid, solid, or gaseous states—without mandating its presence. The broader context of these geological observations underlines the ongoing mystery surrounding Mars’ water, emphasizing the need for future missions that can provide deeper geological analyses and advanced seismic profiling.
As scientists continue to scrutinize the implications of these findings, understanding the configuration of water and ice in Mars’ crust remains a critical aspect of planetary science. Not only does this inform our comprehension of Mars’ environmental evolution, but it also nourishes the ongoing discussion regarding the potential for life on the Red Planet and the exploitation of resources for future human missions.
Jakosky’s work indeed reaffirms the complexity of Martian geology and climate. He suggests that determining the true abundance of water in Mars’ crust is a challenging yet crucial endeavor that could substantially enrich our understanding of both Mars’ past and present conditions. The discussions revealed through Jakosky’s scrutiny will undoubtedly influence future research agendas and exploration missions targeting Mars.
Mars serves as a reminder of the intricate dynamics that once governed its atmosphere and geology, initiating a deep investigation into how such cosmic phenomena might correlate with conditions conducive to life elsewhere in the universe. Each step forward in Mars exploration takes us closer to deciphering the nuanced history of our solar neighbor. Furthermore, this knowledge has profound implications for our quests beyond Earth, in our quest to uncover not only our own planet’s past but also the mysteries of extraterrestrial realms.
In summary, as scientists like Jakosky challenge prevailing narratives and advocate for more nuanced interpretations of data, they pave the way for a more comprehensive understanding—one that balances optimism with caution. The exploration of Mars encapsulates both the grandeur of scientific inquiry and the challenges inherent in unraveling the enigma of a world shaped by forces and conditions vastly different from our own.
Subject of Research: Mars’ water presence in the mid-crust
Article Title: Results from the inSight Mars mission do not require a water-saturated mid crust
News Publication Date: 6-Mar-2025
Web References: MAVEN, InSight, InSight Mission Conclusion
References: Jakosky, Bruce et al., "Results from the inSight Mars mission do not require a water-saturated mid crust," Proceedings of the National Academy of Sciences, March 2025.
Image Credits: NASA, PNAS
Keywords
Mars, liquid water, mid-crust, InSight mission, Bruce Jakosky, Martian geology, planetary science, resource exploration, geology, atmosphere, extraterrestrial life, sedimentary history.
