65dBnoiseNov 13, 2022

One more of those rocks that appear as if they fell from the sky and cracked while they were hot.

But that's nothing more than an impression. Science is more than impressions, takes its time to gather data and establish plausible theories and then prove or disprove them. Until then, imagination plays its game.

Processed, cropped MCZ_LEFT
RMC: 30.1172, Sol: 614
LMST: 09:21:39
UTC: 2022-11-11T11:08:01
Credit: #NASA/JPL-Caltech/ASU

#Perseverance #Mars2020 #solarocks #space #crackedRocks

Show thread65dBnoiseNov 15, 2022

One more of those interesting cracked rocks, originally posted here: https://fosstodon.org/@65dBnoise/109281551145475099

Processed MCZ_LEFT
RMC: 30.1096, Sol: 606
LMST: 15:55:00
Credit: #NASA/JPL-Caltech/ASU

#Perseverance #Mars2020 #Solarocks #Space #crackedRocks

65dBnoise (@[email protected])

Attached: 1 image Mythistorema by Giorgos Seferis Remember the baths where you were murdered I woke with this marble head in my hands it tires out my elbows and I don’t know where to put it down. It was falling into the dream as I was coming out of the dream so our life became one and it will be very difficult for it to separate again. (The whole poem in the image description) Processed MCZ_LEFT RMC: 30.1096, Sol: 606 LMST: 15:55:00 Credit: #NASA/JPL-Caltech/ASU #Perseverance #Mars2020 #Solarocks #Space

Fosstodon
Show threadV MartínNov 15, 2022

@65dBnoise speaking about impressions: when I see such cracked larger rocks, I can't help but remember the fallen, regularly fractured boulders of #67P imaged by #ESARosetta

Same but different 🙃

Source: https://planetgate.mps.mpg.de/Image_of_the_Day/public/OSIRIS_IofD_2016-07-25.html

Related science
https://www.aanda.org/articles/aa/full_html/2015/11/aa25975-15/aa25975-15.html

Show thread65dBnoise
@sharponlooker
Beautiful!
Different kind of rocks as you say, and a very different gravity. My gut feeling for the Martian ones is that gravity has played a significant role in their cracking, but IANAG™, so, waiting for the experts to decide.
Nov 15, 2022 at 10:08amWeb
Show threadV MartínNov 15, 2022
@65dBnoise yeah, thermal stress on asteroids & comets is another level of harsh environments. It's a wonder any large boulder remains whole in such bodies
Show threadV MartínNov 15, 2022

@65dBnoise I'd also crack at that kind of temp differences... 😀

Speaking of thermal stresses, a TV recommendation for anyone in the audience grokking Swedish: a comedian-gone-traveller series (think Michael Palin, Richard Ayoade...) on #SVT, visiting most extreme weather places on Earth. #DavidBatra attempting a 5km run on Death Valley was really something 😀

https://www.svtplay.se/hart-vader

Hårt väder

David Batra ger sig ut på sitt livs resa – till jordens kallaste, varmaste, blåsigaste och blötaste platser. Hans uppdrag: att lära sig hur människorna lever i extrema väder.

SVT Play
Show thread65dBnoiseNov 15, 2022
@sharponlooker
Jezero daily temperature differences appear to be less than 100°C. Are such differences enough to fracture seemingly hard solid rocks in a dry environment? Probably not, but we still don't know the composition of those rocks and their physical properties. Maybe there are other parameters that need to be considered for their fracturing, besides generic 'thermal stress', which means that a story/theory needs to be developed to explain what happened and what we see today.
Show threadV MartínNov 15, 2022
@65dBnoise yes, not so extreme diffs, but 3 billion+ years is a loooong time. Take that rock for example (assuming it's of volcanic origin if the color scale says anything): I can still imagine it having been transported long distances in large floods (rounded sides at the bottom) and having spent some Myrs under water with corresponding alteration. Its final location & aspect can be a combination of erosion and dislodgment.
Show thread65dBnoiseNov 15, 2022

@sharponlooker
In 3 billion years anything can happen, almost everywhere. I made a case for these rocks because I don't remember seeing others cracked like these in Jezero. Maybe I'm wrong.

I think more data is needed and from a lot more places, maybe from outside the delta too, to build a plausible theory about this place. Initially expected were sedimentary rocks, but instead igneous rocks were found in Seitah. And now cracked open rocks here. Maybe that's normal. IANAG™