Gale Crater on Mars seems to have recently had a lot of water

Recent studies led by Imperial College London have brought a surprising twist to the tale of water on Mars‘ Gale Crater.

When you think of Mars, you probably picture a barren, dusty wasteland. Billions of years ago, rivers flowed and lakes filled its craters. But scientists believe the planet dried up eons ago.

This research turns that idea on its head, suggesting that Mars may have had water – and possibly habitable environments – much more recently than we believed.

Water and the Gale Crater

Gale Crater, a vast basin near Mars‘ equator, is the Curiosity rover’s playground. It’s a fantastic place to explore the history of the red planet. The crater can be imagined as a giant lake, with sediments piling up to form the towering Mount Sharp in its center.

Over time, the lake dried. Rivers vanished. Winds piled sand dunes against those sediments, preserving a record of Mars’ transition from wet to dry. Or so we thought.

Gale Crater sandstone hints at water

The researchers studied wind-blown sandstone layers high on Mount Sharp within Gale Crater specifically within an area known as the Feòrachas structure.

These layers, created in a supposedly bone-dry era of Martian history, didn’t look right. Instead of neatly stacked, they were warped and twisted.

“Usually, the wind deposits sediment in a very regular, predictable way,” explained study co-author Amelie Roberts.

“Surprisingly, we found that these wind-deposited layers were contorted into strange shapes, which suggests the sand had been deformed shortly after being laid down. These structures point to the presence of water just below the surface.”

So, what deformed the sand?

Pressurized groundwater

“The sandstone revealed that water was probably abundant more recently and for longer than previously thought – but by which process did the water leave these clues?” asked study lead author Dr. Steven Banham. The sand could’ve warped as pressurized water seeped up, nudging the sand grains around.

Frozen ground

Perhaps water froze and then thawed repeatedly, the ice pushing and pulling the sand into contortions. Dr. Banham noted: “This water might have been pressurized liquid, forced into and deforming the sediment; frozen, with the repeat freezing and thawing process causing the deformation; or briny, and subject to large temperature swings.”

Brines

It’s also possible that extremely salty water (brine) flowed near the surface. Brines handle extreme cold better than pure water, and wild temperature swings in the Martian desert could’ve caused strange effects.

Extended presence of water on Mars

“What’s clear is that behind each of these potential ways to deform this sandstone, water is the common link,” explained Dr. Banham.

Interestingly, scientists agree Mars lost its surface water long ago. These warped sand layers prove something different. It seems water was hanging around longer than we thought, lingering underground even as the surface turned to desert.

Significance of water in the Gale Crater

The discovery matters because of water persisting in Mars’ Gale Crater means potential for life. If water lingered in Martian rocks, perhaps some kind of simple life took refuge there, eking out an existence long after lakes and rivers vanished.

“The layers of sediment in the crater reveal a shift from a wet environment to a drier one over time – reflecting Mars’ transition from a humid and habitable environment to an inhospitable desert world,” explained Roberts.

“But these water-formed structures in the desert sandstone show that water persisted on Mars much later than previously thought.”

Mars rocks: Not off the list for life

Previously, dry Martian deserts were low on the list of places to look for traces of past life – biosignatures.

“Determining whether Mars and other planets were once able to support life has been a major driving force for planetary research,” said Dr. Banham. “Our findings reveal new avenues for exploration – shedding light on Mars’ potential to support life and highlighting where we should continue hunting for new clues.”

“The search for life, whether Mars once harbored it or if other planets could, has driven space exploration for decades. Our findings open entirely new possibilities – they point us to places with the potential to answer those big questions.”

Don’t let those dusty landscapes fool you. When it comes to water – and potential life – Mars might still have a few secrets hiding beneath its barren surface.

The study is published in the journal Geology.

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