Fresh hints concerning the ancient water on Mars

NASA's Curiosity rover has embarked on a new exploration journey across a fresh region of Mars, potentially shedding light on the timeline of when liquid water vanished from the planet's surface once and for all.

Mars, billions of years ago, boasted a much wetter and likely warmer climate compared to its current state.

As Curiosity traverses through and eventually crosses the Gediz Valli's channel—an intricate, serpentine feature that bears resemblance to being sculpted by an ancient river—scientists anticipate gaining insights into Mars' more Earth-like past.

This prospect has piqued the interest of scientists. The rover's team is on a quest to uncover evidence that would validate the mechanism responsible for carving the channel into the underlying bedrock.

The steepness of the formation suggests that wind erosion is an unlikely candidate. Instead, rapid, wet landslides known as debris flows or the force of a river transporting rocks and sediment could have possessed sufficient energy to shape the bedrock.

Subsequently, the channel became filled with boulders and debris, prompting scientists to eagerly investigate whether these materials were transported by debris flows or dry avalanches.

Since 2014, Curiosity has been ascending the foothills of Mount Sharp, towering 3 miles (5 kilometers) above the floor of Gale Crater.

The layers within this lower region of the mountain were gradually formed over millions of years amidst the fluctuations of the Martian climate.

This geological record offers scientists a unique opportunity to examine the evolution of both water and the chemical building blocks necessary for life over time.

For instance, one section of these foothills contains a layer abundant in clay minerals, indicating extensive interaction between water and rock in the past.

Currently, the rover is investigating a layer enriched with sulfates—salty minerals that typically crystallize as water evaporates.

Exploring the channel thoroughly will require several months, and the insights gained from this exploration could potentially revise the timeline for the formation of Mount Sharp.

Following the deposition of sedimentary layers by wind and water on the lower slopes of Mount Sharp, prolonged erosion processes gradually exposed the layers visible today.

Only after these extensive processes, including periods of intense aridity when the surface of Mount Sharp resembled a sandy desert, could the Gediz Valli's channel have been sculpted.

Scientists speculate that the boulders and debris filling the channel originated from higher elevations on the mountain, inaccessible to Curiosity.

This offers the team a glimpse into the types of materials present at those altitudes.

"If the channel or the debris pile were formed by liquid water, that's particularly intriguing.

It would suggest that relatively late in the narrative of Mount Sharp—following an extended dry spell—water resurged, and significantly so," remarked Ashwin Vasavada, Curiosity's project scientist at NASA's Jet Propulsion Laboratory in Southern California.

This explanation aligns with one of the most astonishing revelations uncovered by Curiosity during its ascent up Mount Sharp: Water appears to have fluctuated in cycles, rather than gradually diminishing as the planet transitioned to a drier state.

These cycles are evident in various geological features, including evidence of mud cracks, shallow saline lakes, and, directly beneath the channel, catastrophic debris flows that accumulated to form the extensive Gediz Valli's ridge.

In the past year, Curiosity undertook a challenging climb to investigate the ridge, which extends across the slopes of Mount Sharp and appears to emanate from the terminus of the channel, indicating a cohesive geological system linking both features.

For More Detail: Update92