/sci/ - Science & Math

>>10731850
Those are river rocks.

>>10731850
>River rocks
>beach sand

>mars
If true it means there are probably fossils there too and that doomsday fears are watr

>>10731850
The dimples prove that those rocks got rained on over time for a long time.

>>10731850
Also the sand granules have water content. Some deserts on earth are drier than the environment you pictured, which makes me doubt that’s on Mars.

>>10731850
That NASA JPL only selectively gives us high resolution pics of the ground there and usually gives us compressed shit instead, claiming that it ‘has to be’ even though photos like this exist.

>>10731884
That sand doesn't look like beach sand. It's meteor dust.

>>10731909
>meteor dust
No, that’s clearly sand with a bit of moisture. Sand is a product of weather erosion. This is consistent with the river rocks being eroded smooth and habing rain dimples.

>>10731909
It would be igneous from the heat of impact. There would be no river rocks formed from a meteor hitting. It’s smooth river rocks and sand like you’d find in a dry lake or riverbed on earth.

>>10731850

>>10731850
goape um

>>10731850
That Mars was once geologically active.

>>10731850
Are there and photos of the underside of those pebbles? The sand is abrasive and prevailing wind direction is not obvious in the picture though windspeeds could be calculated by measuring the size of mobile granules if we had scale.

Is it possible the rounding is caused by wind erosion not water erosion?

I would like to draw your attention to what I believe to be the focal point of the image. Near the center of the image there is a pebble with a broken edge. This fresh face of the stone has rounded edges implying recent erosion/scouring.

>>10732297
I remember getting stoned and doing this with puffy clouds.

>>10731850
Mars has dust storms several hundred km/h of extremely fine grain silica particles, and the effect is like sandpaper on stone over time.

This is well known OP. It's often cited as one the greatest difficulties of sending humans to Mars. We would need to invent exosuits that won't get torn apart by violent fine grain sandstorms.

>>10731881
Or polished by blown sand.

>>10731884
>If true it means there are probably fossils there too
I think you left out a step in your chain of reasoning there.

>and that doomsday fears are watr
Wat?

>>10734667
Isn't the atmospheric pressure so low that it wouldn't pose an immediate threat at all? I'm sure it erodes over a long period of time and creates static buildup, but even the largest global duststorms probably feel like a spring breeze to someone in a suit.

>>10734667
>>10734720
>>10733119
Wind erosion creates a sharp edge on top of the rock though. Or a point, if the wind comes from all directions at the same rate.
This doesn't look like wind erosion at all, especially if these rocks have been lying there forever.

>>10734903
See >>10734760

The wind is at low pressure and these rocks have probably been exposed for several million years.

>>10731850
Geologist here, could you please post more? asking for a friend

>>10735213
>wind erosion doesn’t look like these rocks on earth.
>water erosion causes rocks exactly like these on earth.

>therefore it’s wind erosion.
What??

>>10735213
>magical fantasy wind
OR
>what it looks like (river rocks)
If the wind was too weak to erode the rocks like wind erosion should, and no water hit them, they wouldn’t erode into river rocks even after millions of years.
Occam’s razor says our first guess should be that these are river rocks until shown otherwise.

>>10732297
It's not a snail, it's clearly an English Brig.

>>10731850
We can learn Mars had pebbles. How about this image?

>>10734760
>Isn't the atmospheric pressure so low that it wouldn't pose an immediate threat at all?

The wind/atmosphere is not the abrasive part of a dust-storm. It's the hard, sharp little particles of dust. If the atmosphere is sufficient to lift the dust during a storm, that's all that matters.

>>10737017
We can learn that in a series of sufficiently grainy over-zoomedimages, you can eventually find a good example of pareidolia.

>>10737020
To clarify, I am not saying that these pebbles were not rounded by flowing water carrying sand and dust, as opposed to the atmosphere carrying sand and dust. I have no opinion on that.

We do know that flowing water has existed and may still form time to time exist on Mars. We also know that dust storms happen on Mars.

I'm just saying that a comparatively rarefied atmosphere doesn't change the abrasiveness of the dust it carries.

>>10735213
>The wind is at low pressure
Low pressure wind would create the same shape as on earth because it would need to have a very high velocity to even lift the abrasive grains.

Also, I don't see any kind of dune-like pattern on the sand that would suggest a wind- and leeward side of these rocks.