APOD: Mars Rock Rochette (2021 Aug 28)

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APOD: Mars Rock Rochette (2021 Aug 28)

Post by APOD Robot » Sat Aug 28, 2021 4:06 am

Image Mars Rock Rochette

Explanation: Taken on mission sol 180 (August 22) this sharp image from a Hazard Camera on the Perseverance rover looks out across a rock strewn floor of Jezero crater on Mars. At 52.5 centimeters (21 inches) in diameter, one of the rover's steerable front wheels is at lower left in the frame. Near center is a large rock nicknamed Rochette. Mission planners don't want to avoid Rochette though. Instead Perseverance will be instructed to reach out with its 2 meter long robotic arm and abrade the rock's surface, to determine whether it has a consistency suitable for obtaining a sample, slightly thicker than a pencil, using the rover's coring bit. Samples collected by Perseverance would be returned to Earth by a future Mars mission.

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Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by Ann » Sat Aug 28, 2021 5:24 am

Astronaut: Mom, I'm here now!

(Twenty minutes of silence)

Mom: Thank God you are there and you are safe!

(Twenty minutes of silence)

Astronaut: Yeah, I'm fine! How are you?

(Twenty minutes of silence)

Mom: Oh, I'm fine, dear, except my old sciatica is acting up a bit.

(Twenty minutes of silence)

Astronaut: Maybe you should see that Doc again.

(Twenty minutes of silence)

Mom: Tsk, tsk, don't you worry about me! Tell me, what is it like there on Mars? What can you see?

(Twenty minutes of silence)

Astronaut: Rocks.


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Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by De58te » Sat Aug 28, 2021 9:07 am

What I think might be scientifically interesting is if you look at the hi res closeup of today's photo is that all the rocks and pebbles near the rover have sharp, jagged edges. In direct opposition to the rounded blueberry pebbles that the Opportunity Rover found. So what happened to the round weathering of rocks theory that being in an ancient ocean would produce? Is Perseverance's location above the Mars sea level?

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Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by neufer » Sat Aug 28, 2021 12:10 pm

De58te wrote:
Sat Aug 28, 2021 9:07 am

What I think might be scientifically interesting is if you look at the hi res closeup of today's photo is that all the rocks and pebbles near the rover have sharp, jagged edges. In direct opposition to the rounded blueberry pebbles that the Opportunity Rover found. So what happened to the round weathering of rocks theory that being in an ancient ocean would produce? Is Perseverance's location above the Mars sea level?
https://en.wikipedia.org/wiki/Glacier#Roches_moutonn%C3%A9es wrote: <<Roches moutonnées: Passage of glacial ice over an area of bedrock may cause the rock to be sculpted into a knoll called a roche moutonnée, or "sheepback" rock. Roches moutonnées may be elongated, rounded and asymmetrical in shape. They range in length from less than a meter to several hundred meters long. Roches moutonnées have a gentle slope on their up-glacier sides and a steep to vertical face on their down-glacier sides. The glacier abrades the smooth slope on the upstream side as it flows along, but tears rock fragments loose and carries them away from the downstream side via plucking.>>

:arrow: Rock Rochette = Propeller blade of Martian Titanic :?:
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Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by Ann » Sat Aug 28, 2021 12:21 pm

Right, Art - I was going to say that all the big rocks have flat tops, as if a mighty sheet of ice once passed over them.


SpongeBob SquarePants picked himself up and dusted himself off after that humongous ice sheet squeezed him to the ground by pushing and grinding and flattening everything in its path.

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Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by orin stepanek » Sat Aug 28, 2021 1:57 pm

PIA24767_1067.jpg
All the Mars rocks seem ti be reddish brown. Is that from Iron?
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Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by heehaw » Sat Aug 28, 2021 2:35 pm

Thank you Ann! (I am a positive guy, and I don't take any pleasure in being negative, but, sad to say, Mars is ... a dump.)

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Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by Chris Peterson » Sat Aug 28, 2021 2:39 pm

heehaw wrote:
Sat Aug 28, 2021 2:35 pm
Thank you Ann! (I am a positive guy, and I don't take any pleasure in being negative, but, sad to say, Mars is ... a dump.)
But as the only paleoinhabitable planet in the Solar System, it's a goldmine for scientific exploration (by robots, of course).
Chris

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Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by Ann » Sat Aug 28, 2021 2:52 pm

Chris Peterson wrote:
Sat Aug 28, 2021 2:39 pm
heehaw wrote:
Sat Aug 28, 2021 2:35 pm
Thank you Ann! (I am a positive guy, and I don't take any pleasure in being negative, but, sad to say, Mars is ... a dump.)
But as the only paleoinhabitable planet in the Solar System, it's a goldmine for scientific exploration (by robots, of course).
What, Chris? You mean the Earth wasn't paleoinhabitable?

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Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by Chris Peterson » Sat Aug 28, 2021 3:18 pm

Ann wrote:
Sat Aug 28, 2021 2:52 pm
Chris Peterson wrote:
Sat Aug 28, 2021 2:39 pm
heehaw wrote:
Sat Aug 28, 2021 2:35 pm
Thank you Ann! (I am a positive guy, and I don't take any pleasure in being negative, but, sad to say, Mars is ... a dump.)
But as the only paleoinhabitable planet in the Solar System, it's a goldmine for scientific exploration (by robots, of course).
What, Chris? You mean the Earth wasn't paleoinhabitable?
Now it's just habitable!
Chris

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Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by orin stepanek » Sat Aug 28, 2021 3:32 pm

Chris Peterson wrote:
Sat Aug 28, 2021 3:18 pm
Ann wrote:
Sat Aug 28, 2021 2:52 pm
Chris Peterson wrote:
Sat Aug 28, 2021 2:39 pm


But as the only paleoinhabitable planet in the Solar System, it's a goldmine for scientific exploration (by robots, of course).
What, Chris? You mean the Earth wasn't paleoinhabitable?
Now it's just habitable!
8-) :D Hope we keep it that way!
Orin

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Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by Chris Peterson » Sat Aug 28, 2021 3:58 pm

orin stepanek wrote:
Sat Aug 28, 2021 3:32 pm
Chris Peterson wrote:
Sat Aug 28, 2021 3:18 pm
Ann wrote:
Sat Aug 28, 2021 2:52 pm


What, Chris? You mean the Earth wasn't paleoinhabitable?
Now it's just habitable!
8-) :D Hope we keep it that way!
Oh, it will remain habitable for another billion years or more. Likely not for us... but the Universe doesn't much care about that.
Chris

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Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by johnnydeep » Sat Aug 28, 2021 3:59 pm

Chris Peterson wrote:
Sat Aug 28, 2021 3:18 pm
Ann wrote:
Sat Aug 28, 2021 2:52 pm
Chris Peterson wrote:
Sat Aug 28, 2021 2:39 pm


But as the only paleoinhabitable planet in the Solar System, it's a goldmine for scientific exploration (by robots, of course).
What, Chris? You mean the Earth wasn't paleoinhabitable?
Now it's just habitable!
I had also thought that Venus could have been habitable long ago before the run-away greenhouse effect ruined it?
--
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Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by johnnydeep » Sat Aug 28, 2021 4:03 pm

--
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."

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Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by Chris Peterson » Sat Aug 28, 2021 4:11 pm

johnnydeep wrote:
Sat Aug 28, 2021 3:59 pm
Chris Peterson wrote:
Sat Aug 28, 2021 3:18 pm
Ann wrote:
Sat Aug 28, 2021 2:52 pm


What, Chris? You mean the Earth wasn't paleoinhabitable?
Now it's just habitable!
I had also thought that Venus could have been habitable long ago before the run-away greenhouse effect ruined it?
It's possible. Not much is known about the early history of Venus. But Mars was once habitable, with a high degree of confidence.
Chris

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Bric

Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by Bric » Sat Aug 28, 2021 7:02 pm

I've been curious about the thinking about Percy's sampling. It puts the samples in containers and drops them for a later mission to pick up, right? But if we develop a future rover with the capability of returning the samples, why doesn't it just take the samples itself? Alternatively, Percy could put the sample containers back into its rack and carry them with it. The rover will be a lot easier for a future mission to find than dozens of tubes buried in the sand.

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Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by Chris Peterson » Sat Aug 28, 2021 7:35 pm

Bric wrote:
Sat Aug 28, 2021 7:02 pm
I've been curious about the thinking about Percy's sampling. It puts the samples in containers and drops them for a later mission to pick up, right? But if we develop a future rover with the capability of returning the samples, why doesn't it just take the samples itself? Alternatively, Percy could put the sample containers back into its rack and carry them with it. The rover will be a lot easier for a future mission to find than dozens of tubes buried in the sand.
The plan is that all the samples will be cached in just one place. They are stored on the rover and periodically deposited at the cache site. Presumably not on the rover after that because collecting the cache is easier if they're placed so that the rover doesn't get in the way of the collection. This also reduces the risk of losing all of the samples if the rover fails in an inaccessible location.
Chris

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Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by neufer » Sat Aug 28, 2021 8:03 pm

Chris Peterson wrote:
Sat Aug 28, 2021 2:39 pm
heehaw wrote:
Sat Aug 28, 2021 2:35 pm

(I am a positive guy, and I don't take any pleasure in being negative, but, sad to say, Mars is ... a dump.)
But as the only paleoinhabitable planet in the Solar System, it's a goldmine for scientific exploration (by robots, of course).
https://en.wikipedia.org/wiki/Coprolite wrote:
<<A coprolite (also known as a coprolith) is fossilized feces. Coprolites are classified as trace fossils as opposed to body fossils, as they give evidence for the animal's behaviour (in this case, diet) rather than morphology. The name is derived from the Greek words κόπρος (kopros, meaning "dung") and λίθος (lithos, meaning "stone"). They were first described by William Buckland in 1829. Prior to this they were known as "fossil fir cones" and "bezoar stones". They serve a valuable purpose in paleontology because they provide direct evidence of the predation and diet of extinct organisms. Coprolites may range in size from a few millimetres to over 60 centimetres.

Coprolites, distinct from paleofeces, are fossilized animal dung. Like other fossils, coprolites have had much of their original composition replaced by mineral deposits such as silicates and calcium carbonates. Paleofeces, on the other hand, retain much of their original organic composition and can be reconstituted to determine their original chemical properties, though in practice the term coprolite is also used for ancient human faecal material in archaeological contexts.>>
https://en.wikipedia.org/wiki/Midden wrote:
<<A midden is an old dump for domestic waste which may consist of animal bone, human excrement, botanical material, mollusc shells, potsherds, lithics (especially debitage), and other artifacts and ecofacts associated with past human occupation. These features, therefore, provide a useful resource for archaeologists who wish to study the diets and habits of past societies. Middens with damp, anaerobic conditions can even preserve organic remains in deposits as the debris of daily life are tossed on the pile. Each individual toss will contribute a different mix of materials depending upon the activity associated with that particular toss. During the course of deposition sedimentary material is deposited as well. Different mechanisms, from wind and water to animal digs, create a matrix which can also be analysed to provide seasonal and climatic information. In some middens individual dumps of material can be discerned and analysed.

The word is of Scandinavian via Middle English derivation (from early Scandinavian; Danish: mødding, Swedish regional: mödding). In the animal kingdom, some species establish ground burrows, also known as middens, that are used mostly for food storage. For example, the North American red squirrel usually has one large active midden in each territory with perhaps an inactive or auxiliary midden. A midden may be a regularly used animal toilet area or dunghill, created by many mammals, such as the hyrax, and also serving as a territorial marker. Octopus middens are piles of debris that the octopus piles up to conceal the entrance of its den. Octopus middens are commonly made of rocks, shells, and the bones of prey, although they may contain anything the octopus finds that it can move.>>
Fox's Book of Martyrs ** CHAPTER XV wrote: <<like a *BUTCHER* he lived, and like a *BUTCHER* he died,
. and like a carrion was buried in *a DUNGHILL*.
>>
Anthony Holden: The Man Behind the Genius wrote: <<We know that by 1552 John Shakespeare was living on the north-eastern
side of town, in Henley Street, thanks to his ignominious debut in the
town records on 29 April: fined a shilling, along with Humphrey Reynolds
and Adrian Quiney, for making an unauthorised *DUNGHILL*, sterquinarium,
or midden heap in front of the house of a neighbour, the wheelwright
William Chambers. In those days of the plague, a fine equivalent to two
days' pay for an artisan was a suitably stern judgement on those too
idle to use the communal muck-hill at the rural end of the street.
>>
Psalms 113:7 wrote: He raiseth up the poor out of the dust,
. and lifteth the needy out of the *DUNGHILL*;
. That he may set him with princes,
. even with the princes of his people.
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Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by neufer » Tue Sep 14, 2021 2:38 am

neufer wrote:
Sat Aug 28, 2021 12:10 pm
De58te wrote:
Sat Aug 28, 2021 9:07 am

What I think might be scientifically interesting is if you look at the hi res closeup of today's photo is that all the rocks and pebbles near the rover have sharp, jagged edges. In direct opposition to the rounded blueberry pebbles that the Opportunity Rover found. So what happened to the round weathering of rocks theory that being in an ancient ocean would produce? Is Perseverance's location above the Mars sea level?
https://earthobservatory.nasa.gov/images/148822/fossil-fjords-in-namibia wrote:
Fossil Fjords in Namibia
by Kathryn Hansen.

<<Northwestern Namibia is not your typical desert landscape. Valleys dissect plateaus, creating striking vistas across the hot, dry region in southwest Africa. While these valleys are extremely old—with origins dating back hundreds of millions of years—they are remarkably well preserved.

New research indicates that the valleys are ancient relics of a time long before dinosaurs walked the Earth—when Africa was close to the South Pole, still part of the supercontinent Gondwana, and covered with ice. The flow of the ice cut into the land and eventually carved out long, narrow valleys that filled with seawater and formed fjords. Somehow, these ancient fjords have avoided being erased by erosion, uplift, and other geological processes that usually level off this kind of terrain. In fact, the area is so well preserved that scientists call it a “fossil glacial landscape.” “One who looks at these valleys has a snapshot of what the fjords looked like 300 million years ago, except that the ice here has long disappeared,” said Pierre Dietrich, a scientist at University of Rennes and lead author of the study published in Geology.

Some of the region’s U-shaped “fossil fjords” (called paleofjords by geologists) are visible in elevation data from the Shuttle Radar Topography Mission (SRTM). The fossil fjords were carved around 300 million years ago during the Late Paleozoic icehouse, a period when Earth’s climate was cool and Gondwana was heavily glaciated. Today, analogs exist in the ice-carved fjords of Norway and Greenland. Although these modern examples are larger in scale, the land-ice processes are thought to be much the same.

Carved under thick flowing ice sheets that later shrank, the valleys still display evidence of their icy past. The researchers found traces of moraines—accumulations of rocks and debris moved by glacial ice—plastered on valley walls. Ice has etched scratches and grooves into the rocks (striae) and in other places sculpted them into rounded knolls (whalebacks).

As the glaciers retreated, seawater flowed into the fjords and deposited sediments. Namibia’s fjords slowly filled with more and more sediment, which likely played an important role in preserving them. Erosional processes later began to remove the sediments, leaving behind the stronger rock of the original fjords. “Nowadays we see the original shape of the fjords as they were when occupied by the ice,” Dietrich said. “The striae looked so fresh and pristine in Namibia that we first thought we had discovered traces of recent glaciers.”
>>
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Re: APOD: Mars Rock Rochette (2021 Aug 28)

Post by neufer » Tue Sep 14, 2021 10:29 pm

https://en.wikipedia.org/wiki/Mars_sample-return_mission#History wrote:
Click to play embedded YouTube video.
<<For at least three decades, Western scientists have advocated the return of geological samples from Mars. One concept was studied with the Sample Collection for Investigation of Mars (SCIM) proposal, which involved sending a spacecraft in a grazing pass through Mars upper atmosphere to collect dust and air samples without landing or orbiting.

The Soviet Union considered a Mars sample-return mission, Mars 5NM, in 1975 but it was cancelled due to the repeated failures of the N1 rocket that would have been used to launch it. A double sample-return mission, Mars 5M (Mars-79) planned for 1979, was cancelled due to complexity and technical problems.

In early 2011, the National Research Council (NRC)'s Planetary Science Decadal Survey, which laid out mission planning priorities for the period 2013–2022 at the request of NASA and the National Science Foundation (NSF), declared a MSR campaign its highest priority Flagship Mission for that period. In particular, it endorsed the proposed Mars Astrobiology Explorer-Cacher (MAX-C) mission in a "descoped" (less ambitious) form, although this mission plan was officially cancelled in April 2011.

In September 2012, the United States' Mars Program Planning Group endorsed a sample-return after evaluating long-term Mars' plans. The key mission requirement for the Perseverance rover was that it must help prepare NASA for its MSR campaign, which is needed before any crewed mission takes place. Such effort would require three additional vehicles: an orbiter, a fetch rover, and a two-stage, solid-fueled Mars ascent vehicle (MAV). In April 2020, an updated version of the mission was presented. On 1 September 2021, a second sampling attempt on a rock, named "Rochelle", was successful.>>
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