Turns out rocks are rocks. (I’m a geologist I an I approve of this message)
Interesting that Dean Norris was on Mars and has a special interest inrocksminerals.Hey you show some got dang respect. He knew it was an ugly planet, a bug planet, and he did something about it. No more bugs on Mars. You’re welcome.
Those particular rocks seem to be sandstone, though… which would pretty much be proof of liquid water having existed at some point.
Rocks are rocks, sure… but rocks tell stories, and these ones are telling a story that, while common and somewhat uninteresting on Earth, is quite interesting indeed when told on Mars.
You are totally right. I was going to make a big post about how they actually formed but I deleted it halfway through. These rocks are definitely significant in that the same processes on earth happen on Mars so we can infer how they were deposited and formed. Hence my shitty first comment, rocks are rocks.
Dirt is dirt.
Surprisingly less true!
I cum mud!
Aren’t the layers in the rock showing that water was definitely present on Mars, and that they’re formed by sediment being deposited and forming into sedementary rock over time?
I could be wrong, but I don’t think so in this case. Water would likely create more variation in banding where some groupings of layers is present and distinct. What I see in the differences at higher levels appears to be from exposure to wind and solar temperature fluctuations due to exposure. It looks too linear from top to bottom. With water I expect those more distinct sections of banding like you see on the Earth pic side. Maybe there was a lot more or less rain for a time due to a mountain range that came and went, or a local sea or large water basin. Those layers are deep time and more like the slow accumulation of an average dust before wind patterns shift significantly or some event shifts the composition like exposure of a different large rock unit to winds regionally. It is hard for humans to grasp deep time like this.
I’m not a geologist but I’ve read up on it a fair bit.
This Mars photo appears to be sandstone.
On earth sandstone is usually associated with ancient rivers, lake shores, and sea shores. But also sand dune fields.
The thing with sandstone though, is it’s not just sand. Rather, it’s sand plus time plus pressure plus cementation.
Now, the time part is obvious. What’s sandstone now was sand a long ass time ago (usually).
Pressure? That’s a little harder to understand for me here. Has mars ever had tectonic stuff going on to bury it (and hence have pressure applied), followed by erosion and uplift? Or am I incorrect and pressure is not a necessary condition? Maybe sandstone without pressure is a thing it’s just weaker and/or less dense? Maybe layers of volcanic basalt or something could have a similar effect? I don’t know and would love to have someone more knowledgeable fill this part out.
Cementation? This part, I’m nearly certain, REQUIRES water. On earth anyway, this happens when ground water absorbs chemicals from other rock/stuff (for example carbonates from sea shells, but there’s lots of other chemicals that can do this), then flows through the beds of buried sand, and some of those chemicals are deposited along with magical chemistry stuff happening, and your sand becomes sand stone.
So I don’t 100% know that the short answer to your question is “yes”, but I’m leaning towards a solid “yeah, probably, but I’m not a real geologist and Mars isn’t a real Earth so I dunno”.
Apparently, sandstone takes FAR less time to form than most people think. Apparently, some sandstone deposits have been found with roman artefacts inside. They were normal sand at the time and turned to sandstone since then.
Basically, it would take far less time than you would think to form sandstone on Mars. It’s still proof of liquid water, but the lower end of the time estimate can be FAR shorter than you first think.
There’s a non zero chance that Mars is a remnant of the planetary impact that occured to the Earth ~ 3.5 BYA. The issue is that’s a really loose hypothesis, but the speculation is that Theia - which impacted Gaia (old Earth) was an ice planet / water world, which gave us most of our oceans.
Evidence of water evaporation on Mars therefore makes sense, as a catastrophic effect (such as planetary impact) would indeed cause the atmosphere to boil off, leaving behind these dry lakes and riverbeds.
I personally haven’t spent enough time on Mars to make a substantial conclusion, there wasn’t enough time to do any science between the sheer insanity of basic survival on a planet that seems uniquely designed to kill you and crush your spirit before doing so.
I totally approve of your analysis however, and it’s proof why geologists deserve a seat on the interstellar jumpships :3
No, Mars was not formed by the moom-forming impact event between Gaia and Theia. The moon is the remnant you’re talking about, not Mars.
Also, a recent paper shed some doubt on the impact theory (apparently Earth and Moon isotopes are too similar), so the impact might not have happened or it might have been different than previously thought (glancing and causing the proto-Earth to spin itself apart, or strong enough to completely melt and mix both objects).
In any case, though, yeah, Mars has the wrong composition, size, and orbit for it to have been involved in any impact with Earth. The mistake probably came from Theia often being described as ‘Mars sized’.
I think they mean Mars could be Theia.
I think the fact that it’s really far away, in a circular orbit, and doesn’t have a big chunk missing is still a good sign that mars isn’t theia
Why would it have a chunk missing after all this time? If it did could we even tell? Whatever it was isn’t still in the area so being far away may not mean much. Circular orbit is probably biggest reason it’s likely not Mars, although it could have evened out relatively recently.
This simulation shows the Mars sized object merging with Earth so there goes that theory.
Yup!
Sediment gathers at the bottom of a lake or sea. Builds up deeper and deeper layers. Each layer is formed by a sediment deposition event. Each layer you go down is going further into the past of that former water body.
Because sedimentary rock requires standing bodies of liquid to form, they are only found on Earth and Mars (and maybe Dragonfly will find sedimentary deposits on Titan which would be very different in chemistry).
Think so. That’s what I came here to ask
I came to ask which picture is which then noticed the blue sky duh 😂
Or the title.
OMG I’m being leftright-shamed
Soo we have a better GPU
It’s just the ray tracing
Take my upvote!
Wheres the Gorn?
Looking for a big rock
They’re gorn.
I’ve been to the Vasquez Rocks where that was shot. It’s right by a freeway that definitely also existed in the 60s. They had to use some very creative camera work in terms of where they pointed it. It’s kind of impressive.
Those clouds are doing a lot of talking in the picture on the right
That’s how I figured which was which (I don’t have the ability to quickly figure out left from right like most people have, so that left me time to play at guessing).
I don’t have the ability to quickly figure out left from right
As a kid I used to use which wrist my watch was on as a reference (I couldn’t tell right from left, but I did know which wrist to put it on, most of the time). Of course with smartphones being a thing I no longer use a watch, but at this point the brain seems to have learnt to do it automatically. A ring, or wristband, or something like that would also work, probably.
But even then… do they mean my right, or the screen’s right…? Or the picture’s…? I never know, and a watch won’t help with that…
In my case I remember with which hand I use the mouse. But I never could get this to be automatic.
I still sometimes hold my hands in front of me and see which one makes a natural L shape with index finger and thumb.
Good to know I’m not alone with this “disability”.
Looks like a nice day on Mars. Apart from it being -70C out.
So no Mr Bluesky on Mars?
If only he would tell us why he had to hide away, for so long :(
Where did we go wrong?
Mars has blue sunsets though.
Mmmm that’s some good choss! Do you happen to know where the photo on the right was taken? My geoguessr brain wants to put a pin on Kanab, Utah
I believe it’s the Atacama desert in Chile, according to a reverse image search.
Woah, cool, I never would have guessed! I should have thought to use reverse image search, haha. Thanks!
It was harder to identify than I expected, because the article I found was from Chile, and my Spanish is rusty. Lol
I dont know what camera they used but that zoom is crazy
Captured on my Samsung Galaxy s22
Aeolian erosion do be like that though.
Mars looks like Southern California in Star Trek in the 60s.
Says a lot for how much they were able to accomplish thematically with environments like that. Iconic
i wonder if humanoid aliens would be a common thing throughout the universe
like a mass effect sorta thing
Crabs are much more likely. Everything turns into crabs, eventually.
“Everything” with our sort of molecule for storing information. DNA might not be the only way.
It’s not about DNA; it’s about “crab-like” being an optimal shape for something that has to move itself in and manipulate a variety of environments.
It doesn’t matter if it’s an arthropod or a robot. Crab-like is almost always optimal.
Optimal for Earth environments.
A crab body would not work if life evolved on a gas giant.
i was thinking more on the convergent evolution side, since the worlds seem to be similar? but panspermia is a cool concept too.
If it’s gonna be convergent evolution, all the aliens are probably crab people
crab people crab people
That’s a humanoid wet dream! You wouldn’t need a schlob to mebeep for sexy times when you can just whip out the ol’ sausage.
Ah, so Mars is socialist.
Mars hasn’t this nice blue sky. Come on Cohaagen, give these people air… um… I mean an atmosphere.
