Evidence from Gale Crater

Gale Crater, the landing site of Curiosity, is strongly believed to have hosted a lake at some point in its history. Geological features such as clay and sulfate minerals, which typically form in the presence of water, alongside indicators like fans and deltas—characteristics observed on Earth—support this theory. This crater may have contained freshwater that was once clean enough for human consumption. For an insightful overview of Gale Crater and the conditions Curiosity is investigating, check out the introductory video below:

As Curiosity explores the lower regions of Mount Sharp within Gale Crater, it has uncovered signs of a long-standing lake. The rover's ascent has revealed rocks rich in mineral salts, suggesting these deposits formed in salty ponds that experienced cycles of drying and wetting—consistent with a partially functioning hydrological cycle. Future investigations will take Curiosity to the "sulfate bearing unit," where scientists hope to analyze its composition to shed light on Mars' prolonged dry period.

The Geological Journey

Curiosity's journey up the slopes of Mount Sharp is essentially a trip through time, moving from the planet's distant past toward its present. If the sulfate-bearing unit shows a consistent increase in sulfate concentrations, it will indicate a gradual progression toward aridity on Mars without significant reversals. Conversely, if the sediment layers exhibit alternating patterns of moisture and dryness, it would suggest that the planet's drying occurred in a stepwise manner over an extended timeframe.

The mystery of Mars’ Water History

There are substantial questions regarding the duration of water's presence on Mars. The belief in a wetter ancient Mars stems from the observation that craters from the Noachian Era (approximately 4.1 to 3.7 billion years ago) exhibit far greater erosion than those formed during the Hesperian period (3.7 to 3.0 billion years ago). Gale Crater, estimated to have formed between 3.8 and 3.5 billion years ago, falls within this critical transitional phase of the planet's history.

Several theories exist to explain how Mars might have sustained liquid water for billions of years, even amid challenges posed by the dim early Sun. It is posited that early Mars retained heat from radioactive decay within its core. Nonetheless, Mars is considerably smaller than Earth, lacking sufficient heavy elements and the short-lived, high-energy elements necessary for sustaining warmth. The Late Heavy Bombardment is believed to have bombarded Mars with significant impacts, occurring roughly every million years, alongside a much higher frequency of smaller impacts.

The Tharsis Bulge, a massive volcanic region on Mars, may also have influenced the planet's climate. Its sheer mass could have caused 'true polar wander,' shifting the locations of the poles. The cessation of Mars' geomagnetic dynamo and the consequent loss of its magnetic field also likely played a role. Understanding the timeline of water loss on Mars is crucial for grasping the processes that have shaped the planet.

Further Exploration

Now Read:

• NASA’s InSight Lander Beams Back the Sounds of Mars
• Mars Orbiter Finds Giant Cache of Ice on the Red Planet
• Here’s What a Solar Eclipse Looks Like on Mars

The first video titled "Mars Mystery Revealed: Is There Life in the Ice?" explores the potential for life beneath Mars' icy surface. Watch the video to uncover fascinating insights:

The second video titled "Mars study suggests 'hidden ocean' under planet's surface – but there's a catch" delves into the intriguing findings of a possible subsurface ocean. Check it out below for more details: