Revelatory Findings Regarding Debris Flows on Mars

Revelatory Findings Regarding Debris Flows on Mars

The duration of liquid water presence on Mars may have been briefer than previously assumed. Gully formations known as channels, traditionally attributed solely to liquid water, can also originate from the effects of evaporating CO2 ice.

Revelatory Findings Regarding Debris Flows on Mars

A satellite image depicting Martian gully landscapes, captured by HiRISE (High Resolution Imaging Experiment), a camera aboard the Mars Reconnaissance Orbiter (photo no.: ESP_039114_1115). The presence of white CO2 ice is evident on the gully sides. Credit: HiRISE (High Resolution Imaging Experiment), a camera aboard the Mars Reconnaissance Orbiter (photo no.: ESP_039114_1115)

This revelation stems from a recent investigation led by Lonneke Roelofs, a planetary researcher at Utrecht University. "This finding impacts our understanding of water on Mars overall, thereby influencing our quest for signs of life on the planet," remarks Roelofs.

The findings of this study are detailed in the journal Communications Earth and Environment, published this week.



Roelofs elucidates, "The Martian atmosphere comprises 95% CO2." During winter, temperatures plummet to below -120 degrees Celsius, facilitating the freezing of atmospheric CO2. This freezing process enables CO2 gas to directly transform into CO2 ice, bypassing the liquid phase.

This mechanism mirrors frost formation on Earth, where water vapor crystallizes into ice, blanketing the terrain in a white layer. With the advent of warmer spring temperatures and the thin Martian atmosphere, CO2 ice sublimates directly back into gas, circumventing the liquid phase once more.

Roelofs explains, "We term this phenomenon 'sublimation.' The process, due to Mars' low air pressure, is highly explosive. The resultant gas pressure disperses sediment particles, inducing material flow akin to debris flows in terrestrial mountainous regions. These flows possess the capacity to reshape Martian topography, even sans water."

"My research findings suggest that the likelihood of past life existence on Mars is lower than previously surmised."

The notion of CO2 ice serving as a catalyst for Martian landscape formations has long been conjectured by scientists. "However, these suppositions primarily relied on models or satellite analyses," Roelofs clarifies.

"Through experiments conducted in a simulated 'Mars chamber,' we replicated this process under Martian conditions. Utilizing specialized laboratory apparatus, we directly observed this phenomenon. Remarkably, we noted that debris flows instigated by CO2 ice under Martian conditions exhibit similar efficiency to water-driven debris flows on Earth."

Potential for Extraterrestrial Life

Roelofs asserts, "We have concrete evidence of past water presence on Mars. This study does not refute that fact." However, the emergence of life likely necessitates an extended period of liquid water availability. Formerly, the assumption was that these landscape formations resulted from water-driven debris flows, owing to their resemblance to terrestrial equivalents.

"My research now demonstrates that, alongside water-induced debris flows, the sublimation of frozen CO2 can also propel the formation of these Martian gully landscapes. Consequently, this pushes the timeline of water presence on Mars further into the past, diminishing the prospects of Martian life." This realization underscores our uniqueness to a greater extent than previously recognized.

Why Mars?

But what prompts fascination with landscapes situated 330 million km away? "Mars represents our nearest celestial neighbor. It stands as the sole rocky planet within our solar system's 'green zone,' where conditions are conducive to liquid water existence—a prerequisite for life. Thus, Mars offers a potential platform for unraveling the mysteries surrounding the origin of life, including the prospect of extraterrestrial life," Roelofs emphasizes.

"Moreover, studying the genesis of landscape structures on other celestial bodies enables us to transcend our terrestrial boundaries. It prompts novel inquiries, leading to fresh insights into terrestrial processes. For instance, we can draw parallels between gas-driven debris flows on Mars and pyroclastic flows encircling terrestrial volcanoes. Hence, this research has the potential to enhance our comprehension of volcanic hazards on Earth."

QnA

What evidence do we have that there was running liquid water on Mars in the past?

Geological indicators of past water flow include extensive outflow channels shaped by floods, ancient river networks, deltas, and former lakebeds. Additionally, the presence of specific rocks and minerals on the surface suggests formation in a liquid water environment.

What happened to all the water on Mars?

Mars lost its water when it lost its magnetic field and a significant portion of its atmosphere, leaving its surface more exposed to the sun. The water subsequently became trapped within minerals in the Martian crust, potentially remaining there to this day. Despite its current arid state, Mars likely once hosted vast oceans.

Is there any liquid water on Mars?

Recent findings suggest the presence of liquid water beneath the southern polar ice cap of Mars, indicating possible geothermal activity on the planet.

When did Mars lose its water?

Around 3 billion years ago, as Mars' atmosphere gradually thinned, its water evaporated, leading to the desolate, frozen landscape observed today.

What are three interesting facts about Mars?

  1. Named after the Roman God of war, Mars is the fourth planet from the sun.
  2. Dubbed the 'Red Planet' due to its distinctive color.
  3. Mars ranks as the second smallest planet in the solar system, following Mercury.
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