Date: 20/05/2025 18:02:02
From: Bubblecar
ID: 2284184
Subject: Dark streaks on Mars may not come from water after all

First identified in the 1970s by NASA’s Viking mission, long, dark markings snake down Martian slopes, sometimes stretching across Mars’ surface for hundreds of feet. Scientists have watched some of these markings exist for decades, while others, known as “recurring slope lineae,” appear to fade in a single season. Nonetheless, they all starkly stand out against the planet’s dusty red surface.

Given that modern Mars is dry and arid, with temperatures rarely climbing above the freezing point of water, the origin of these streaks has long been a topic of heated debate. For years, they were seen as one of the most compelling signs that liquid water might still exist on Mars, suggesting a rare pocket of habitability on an otherwise arid planet. The leading theory speculated that salty water was seeping from underground sources — like buried ice or subsurface aquifers — allowing it to briefly flow across the cold Martian surface. But new evidence suggests something else might be driving the phenomenon.

“A big focus of Mars research is understanding modern-day processes on Mars — including the possibility of liquid water on the surface,” said Adomas Valantinas, a postdoctoral researcher at Brown University in a statement. “Our study reviewed these features but found no evidence of water. Our model favors dry formation processes.”

…..The geostatistical analysis revealed that slope streaks and recurring slope lineae don’t appear in places where you’d expect to find signs of liquid water or frost. For instance, watery slopes would be expected to face a specific direction, experience extreme temperature swings, or exist in high humidity. Instead, the study found that these streaky features are more common in areas with stronger winds and heavier dust activity.

The researchers say this points to the streaks forming when thin layers of fine dust slide down a steep hillside.

Full Report

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Date: 20/05/2025 23:16:50
From: roughbarked
ID: 2284283
Subject: re: Dark streaks on Mars may not come from water after all

Interesting indeed.

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Date: 20/05/2025 23:50:06
From: Kingy
ID: 2284289
Subject: re: Dark streaks on Mars may not come from water after all

Sometimes when I’m working the bobcat in late summer the sand and dust is so dry that it is not only water repellent, but it repels itself. It flows like water out of the bucket. I always thought that this was the reason behind the “water flows” on Mars.

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Date: 20/05/2025 23:51:25
From: roughbarked
ID: 2284291
Subject: re: Dark streaks on Mars may not come from water after all

Kingy said:


Sometimes when I’m working the bobcat in late summer the sand and dust is so dry that it is not only water repellent, but it repels itself. It flows like water out of the bucket. I always thought that this was the reason behind the “water flows” on Mars.

Morrie would certainly have words on this.

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Date: 21/05/2025 08:51:41
From: ms spock
ID: 2284359
Subject: re: Dark streaks on Mars may not come from water after all

Kingy said:


Sometimes when I’m working the bobcat in late summer the sand and dust is so dry that it is not only water repellent, but it repels itself. It flows like water out of the bucket. I always thought that this was the reason behind the “water flows” on Mars.

Is this a normal thing that you have seen before, or is this new?

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Date: 21/05/2025 08:54:42
From: roughbarked
ID: 2284361
Subject: re: Dark streaks on Mars may not come from water after all

ms spock said:


Kingy said:

Sometimes when I’m working the bobcat in late summer the sand and dust is so dry that it is not only water repellent, but it repels itself. It flows like water out of the bucket. I always thought that this was the reason behind the “water flows” on Mars.

Is this a normal thing that you have seen before, or is this new?

Usual.

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Date: 21/05/2025 08:55:20
From: roughbarked
ID: 2284363
Subject: re: Dark streaks on Mars may not come from water after all

roughbarked said:


ms spock said:

Kingy said:

Sometimes when I’m working the bobcat in late summer the sand and dust is so dry that it is not only water repellent, but it repels itself. It flows like water out of the bucket. I always thought that this was the reason behind the “water flows” on Mars.

Is this a normal thing that you have seen before, or is this new?

Usual.

Well, unless the sand is wet.

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Date: 21/05/2025 09:27:03
From: Bogsnorkler
ID: 2284374
Subject: re: Dark streaks on Mars may not come from water after all

ms spock said:


Kingy said:

Sometimes when I’m working the bobcat in late summer the sand and dust is so dry that it is not only water repellent, but it repels itself. It flows like water out of the bucket. I always thought that this was the reason behind the “water flows” on Mars.

Is this a normal thing that you have seen before, or is this new?

soils in the sw of wa are very hydrophobic.

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Date: 21/05/2025 09:29:13
From: roughbarked
ID: 2284376
Subject: re: Dark streaks on Mars may not come from water after all

Bogsnorkler said:


ms spock said:

Kingy said:

Sometimes when I’m working the bobcat in late summer the sand and dust is so dry that it is not only water repellent, but it repels itself. It flows like water out of the bucket. I always thought that this was the reason behind the “water flows” on Mars.

Is this a normal thing that you have seen before, or is this new?

soils in the sw of wa are very hydrophobic.

Same here and I expect for much of southern Australia.

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Date: 24/05/2025 23:45:40
From: wookiemeister
ID: 2285748
Subject: re: Dark streaks on Mars may not come from water after all

I won’t lie

I find this hard to believe

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