APOD: A Hole in Mars (2020 Mar 01)

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Expand view Topic review: APOD: A Hole in Mars (2020 Mar 01)

Re: APOD: A Hole in Mars (2020 Mar 01)

by Ann » Fri Mar 20, 2020 7:26 am

fertooos wrote: Fri Mar 20, 2020 6:26 am Who was the first to suggest that life on Mars is possible? I remember times when this topic was very popular and discussed on every corner. If it is at least 1% realistic, I would immediately move there from Leeds ... Crazy idea, but sometimes it is useful to imagine mad things. Can you recommend some books to read about Mars and the idea of creating living conditions there?
I don't know who was first to suggest that there might be life on Mars, but Percival Lowell, a wealthy astronomer from Boston, was extremely influential when it came to spreading the idea that there was life on Mars. In the late 1800s, Percial Lowell claimed that there were canals, artificially created waterways, on Mars, and that there therefore must be intelligent beings on Mars who created them. Read more here, where you can also find out a little about H.G. Wells and his novel The War of the Worlds, and Edgar Rice Burroughs and his romantic and swashbuckling adventures set on Mars. Burroughs was the one who gave the Martians green skin, and thus he is responsible for creating the idea of "little green men". 👽

You might also want to see the 2015 movie The Martian, which is about an American astronaut accidentally left behind on Mars when his fellow astronauts leave, and he has to fend for himself on Mars.

Nowadays many scientists believe that simple life forms may very well have existed on Mars in the past, and fossils of such life forms might remain, and just possibly even some simple life forms may still survive on Mars today. It is generally believed that such life forms would have to live underground, since conditions on the Martian surface are generally regarded as too harsh for life as we know it.

Ann

Re: APOD: A Hole in Mars (2020 Mar 01)

by neufer » Fri Mar 06, 2020 3:03 pm

TheArtofWalls wrote: Fri Mar 06, 2020 10:19 am
Why there is a circular crater surrounding this hole remains a topic of speculation
Well, it is a hole in the ground and the ground is made of sand, so I think it is obvious that sand has fallen down the hole. This would explain the perfect conical shape of the crater, the circular border and the absence of ejecta.

If this has still no proper name, I vote for PIT OF CARKOON😜
https://en.wikipedia.org/wiki/Sarlacc wrote: <<The sarlacc (plural sarlacci) first appeared in the film Return of the Jedi (1983) as a multi-tentacled alien beast whose immense, gaping maw is lined with several rows of sharp teeth. The sarlacc in the film inhabits the Great Pit of Carkoon, a hollow in the sand of the desert planet Tatooine. In the original Return of the Jedi, the sarlacc is simply a barbed hole in the desert sand which characters fall into and are consumed; some are pulled into the sarlacc's mouth by its tentacles. In the 1997 Special Edition of the film, computer-generated tentacles and a beak emerge from the opened mouth. Besides Return of the Jedi, the creature and others like it are featured in Star Wars literature.

According to the Star Wars Databank, the sarlacci inhabit remote, inhospitable locations in the galaxy, but defies taxonomic classification, in so far as most texts claim that the sarlacc is an arthropod (as in The Essential Guide to Alien Species and The Wildlife of Star Wars), while its anchored root system and spore-based method of reproduction suggest a plant origin. A sarlacc reproduces by releasing spores through outer space, which arrive on a planet or asteroid, and there excavate a pit to capture prey.

Steve Sansweet's Star Wars Encyclopedia describes the sarlacc as an "omnivorous, multi-tentacled creature with needle-sharp teeth and a large beak". The sarlacc rests at the base of a giant pit where the entirety of its body is buried except for the gaping mouth, which may reach three meters in diameter. The sarlaac uses its four legs to anchor itself underground. Astrophysicist and science fiction author Jeanne Cavelos compares the sarlacc's hunting method to that of the antlion. The sarlacc's mouth also has similarities with that of the lamprey.

Because most sarlacci inhabit isolated environments and rely on prey to stumble into their pit, they rarely feed; the digestive system dissolves prey into nutrients over a period of several thousand years. If no living prey is available, a sarlacc relies on its root system to absorb nutrients. One sarlacc located on an airless moon feeds on cometary material rich in oxygen, hydrogen, carbon, and nitrogen.

The sarlacc's stomach is lined with vessels that attach themselves to a swallowed victim and maws for quick digestion or breaking apart large prey. The maws close when exposed to bright lights. The stomach also contains neurotoxins, which induce hallucinations in prey which "suggest that the sarlacc somehow absorbs the intelligence of all its victims, who live on in disembodied torment". A sarlacc can communicate with its victims through this stolen consciousness: In one Star Wars short story, an unnamed Jedi explains that "sarlacci do interesting things with messenger RNA: over the course of millennia, they can attain a sort of group consciousness, built out of the remains of people they've digested. I talked to such a sarlacc, once a few decades ago.">>

Re: APOD: A Hole in Mars (2020 Mar 01)

by TheArtofWalls » Fri Mar 06, 2020 10:19 am

Why there is a circular crater surrounding this hole remains a topic of speculation
Well, it is a hole in the ground and the ground is made of sand, so I think it is obvious that sand has fallen down the hole. This would explain the perfect conical shape of the crater, the circular border and the absence of ejecta.

If this has still no proper name, I vote for PIT OF CARKOON😜

Re: APOD: A Hole in Mars (2020 Mar 01)

by SpaceCadet » Thu Mar 05, 2020 8:55 am

Chris Peterson wrote: Wed Mar 04, 2020 5:58 am
SpaceCadet wrote: Wed Mar 04, 2020 5:48 am
wildespace wrote: Sun Mar 01, 2020 3:59 pm
Some forms of like don't require oxygen (or any atmosphere really). Thermal vents, even solid rocks. There are organisms feeding off chemical composition.
But wouldn't the lifeform need protection from the solar elements,like radiation? An atmosphere isn't just about providing possible nutrition or an energy source.
You're assuming it lives on the surface. It could be under rock, under ice, underwater. It could also be very tolerant of radiation.
True,i didn't consider a life form that might be protected by the ground. That last point is actually very interesting, bc if possible,the implication is a creature that might survive interplanetary or perhaps even intergalactic space. That's a mind bender right there.

Thanks for the insight!

Re: APOD: A Hole in Mars (2020 Mar 01)

by smitty » Wed Mar 04, 2020 1:53 pm

Regarding SpaceCadet's question about life surviving on Mars, it might be helpful to explore what we know about the world of extremophiles: https://en.wikipedia.org/wiki/Extremophile .

Re: APOD: A Hole in Mars (2020 Mar 01)

by Chris Peterson » Wed Mar 04, 2020 5:58 am

SpaceCadet wrote: Wed Mar 04, 2020 5:48 am
wildespace wrote: Sun Mar 01, 2020 3:59 pm
SpaceCadet wrote: Sun Mar 01, 2020 12:37 pm How is martian life a possibility when there isn't any atmosphere to speak of?
Some forms of like don't require oxygen (or any atmosphere really). Thermal vents, even solid rocks. There are organisms feeding off chemical composition.
But wouldn't the lifeform need protection from the solar elements,like radiation? An atmosphere isn't just about providing possible nutrition or an energy source.
You're assuming it lives on the surface. It could be under rock, under ice, underwater. It could also be very tolerant of radiation.

Re: APOD: A Hole in Mars (2020 Mar 01)

by SpaceCadet » Wed Mar 04, 2020 5:48 am

wildespace wrote: Sun Mar 01, 2020 3:59 pm
SpaceCadet wrote: Sun Mar 01, 2020 12:37 pm How is martian life a possibility when there isn't any atmosphere to speak of?
Some forms of like don't require oxygen (or any atmosphere really). Thermal vents, even solid rocks. There are organisms feeding off chemical composition.
But wouldn't the lifeform need protection from the solar elements,like radiation? An atmosphere isn't just about providing possible nutrition or an energy source.

Re: APOD: A Hole in Mars (2020 Mar 01)

by Chris Peterson » Tue Mar 03, 2020 2:48 pm

smitty wrote: Tue Mar 03, 2020 2:43 pm Anybody know whether other, similar holes have been found on Mars, and if so how many?
Yes, I believe there are others. A half dozen or more. IIRC, a few are not imaged well enough to be certain, but show as dark spots that are suspected to be holes.

Re: APOD: A Hole in Mars (2020 Mar 01)

by smitty » Tue Mar 03, 2020 2:43 pm

Anybody know whether other, similar holes have been found on Mars, and if so how many?

Re: APOD: A Hole in Mars (2020 Mar 01)

by mickwilson200 » Tue Mar 03, 2020 6:09 am

Tongue in cheek: it's obviously ant lions, and those chappies look like something Khan put in Checkov's ears.

Re: APOD: A Hole in Mars (2020 Mar 01)

by neufer » Sun Mar 01, 2020 10:42 pm

Raymond Kenneth Petry wrote: Sun Mar 01, 2020 9:56 pm
Neat circle, no rim-pucker, slightly-left-off-centered ragged bottom hole, no ejecta on the periphery, except a short spillover to its right, 8% rim bevel...suggests a single meteor impact into damp sand-stone (mud volcano shield), removing 17% of the crater, from just-right-off-vertical (back-bounce overspilling), no atmosphere (at-that-time), meteor-shaped-charge penetrating to a sublevel watertable which subsequently evaporated-down (not long ago)...
This little boy replied, beaming, "there must be a Petry in here somewhere!"

Re: APOD: A Hole in Mars (2020 Mar 01)

by Raymond Kenneth Petry » Sun Mar 01, 2020 9:56 pm

Neat circle, no rim-pucker, slightly-left-off-centered ragged bottom hole, no ejecta on the periphery, except a short spillover to its right, 8% rim bevel...suggests a single meteor impact into damp sand-stone (mud volcano shield), removing 17% of the crater, from just-right-off-vertical (back-bounce overspilling), no atmosphere (at-that-time), meteor-shaped-charge penetrating to a sublevel watertable which subsequently evaporated-down (not long ago)...

Re: APOD: A Hole in Mars (2020 Mar 01)

by neufer » Sun Mar 01, 2020 7:48 pm

SteveH wrote: Sun Mar 01, 2020 4:00 pm
My speculation is that being on a volcano, the cavern is a lava tube. The hole is located in a place where the ceiling of the tube was very near the ground surface and, as mentioned before, there was a collapse. The circular crater is what was left after the sandy surface drained into the tube.
My only question is whether the ceiling of these tubes collapsed all on their own
or is their a meteorite or two down there somewhere!.
https://en.wikipedia.org/wiki/Heat_Shield_Rock wrote:
<<Following the identification of Heat Shield Rock as a meteorite, five similar iron meteorites were discovered by Opportunity (informally named "Block Island", "Ireland" "Mackinac Island", "Oileán Ruaidh" and "Shelter island"). Two nickel-iron meteorites were identified by the Spirit rover (informally named "Allan Hills" and "Zhong Shan"). One nickel-iron meteorite has been identified by the Curiosity rover, tagged "Lebanon." In addition, several candidate stony meteorites have also been identified on Mars.>>
https://www.phrases.org.uk/bulletin_board/28/messages/695.html wrote:
<<Worried that their young twin boys had developed extreme personalities --
one was a total pessimist, the other a total optimist -- their parents took them to a psychiatrist.

First the psychiatrist treated the pessimist. Trying to brighten his outlook, the psychiatrist took him to a room piled to the ceiling with brand-new toys. But instead of yelping with delight, the little boy burst into tears. "What's the matter?" the psychiatrist asked, baffled. "Don't you want to play with any of the toys?" "Yes," the little boy bawled, "but if I did I'd only break them."

Next the psychiatrist treated the optimist. Trying to dampen his out look, the psychiatrist took him to a room piled to the ceiling with horse manure. But instead of wrinkling his nose in disgust, the optimist emitted just the yelp of delight the psychiatrist had been hoping to hear from his brother, the pessimist. Then he clambered to the top of the pile, dropped to his knees, and began gleefully digging out scoop after scoop with his bare hands. "What do you think you're doing?" the psychiatrist asked, just as baffled by the optimist as he had been by the pessimist. "With all this manure," the little boy replied, beaming, "there must be a pony in here somewhere!">>

Re: APOD: A Hole in Mars (2020 Mar 01)

by Ann » Sun Mar 01, 2020 7:42 pm

Chris Peterson wrote: Sun Mar 01, 2020 6:40 pm
Astronymus wrote: Sun Mar 01, 2020 6:30 pm
MadCat-75 wrote: Sun Mar 01, 2020 9:11 am The home of the giant ant lions... xD
Hehe, had the same thought. Now I'd like to see those giant Mars ants. :lol2:
I remember this old movie I saw on TV when I was a kid, where martian invaders kidnapped people by somehow making the sand under them open up and swallow them. A really hokey movie, but there was something terrifying about the way people just got sucked into the ground. Thought about that for years when I was on sand!

(The movie, creatively enough, was called Invaders from Mars.)
_
Click to play embedded YouTube video.
We used to have a English Listening Comprehension exercise at my school, where a stuntman and a stunt coordinator were interviewed. The stunt coordinator explained how he created a stunt where a woman really had to be swallowed up by the ground. They dug a deep hole, filled it with peat moss and water, fitted it with an oxygen tank and a lift, and had the stuntwoman step on it and be swallowed up by the ground.

Yes, she survived and was unhurt, too. Well, the stuntwoman survived, not her character in the TV show.

Ann

Re: APOD: A Hole in Mars (2020 Mar 01)

by Chris Peterson » Sun Mar 01, 2020 6:40 pm

Astronymus wrote: Sun Mar 01, 2020 6:30 pm
MadCat-75 wrote: Sun Mar 01, 2020 9:11 am The home of the giant ant lions... xD
Hehe, had the same thought. Now I'd like to see those giant Mars ants. :lol2:
I remember this old movie I saw on TV when I was a kid, where martian invaders kidnapped people by somehow making the sand under them open up and swallow them. A really hokey movie, but there was something terrifying about the way people just got sucked into the ground. Thought about that for years when I was on sand!

(The movie, creatively enough, was called Invaders from Mars.)
_
Click to play embedded YouTube video.

Re: APOD: A Hole in Mars (2020 Mar 01)

by Astronymus » Sun Mar 01, 2020 6:30 pm

MadCat-75 wrote: Sun Mar 01, 2020 9:11 am The home of the giant ant lions... xD
Hehe, had the same thought. Now I'd like to see those giant Mars ants. :lol2:

Re: APOD: A Hole in Mars (2020 Mar 01)

by HellCat » Sun Mar 01, 2020 4:49 pm

I'll upvote SteveH on the lava tube skylight hypothesis.
It might be that we don't see any other skylights because they:
1) Happen infrequently, especially so the more time passes from their formation, and
2) Once open, they are filled in from above. (instantaneously in geologic time frames)

Re: APOD: A Hole in Mars (2020 Mar 01)

by SteveH » Sun Mar 01, 2020 4:00 pm

My speculation is that being on a volcano, the cavern is a lava tube. The hole is located in a place where the ceiling of the tube was very near the ground surface and, as mentioned before, there was a collapse. The circular crater is what was left after the sandy surface drained into the tube.

There may be others like this hole in this or other volcanoe's plumbing system systems. They may or may not be visible from the surface. Presumably, they could be hidden from view where there was enough sand to pile up from the floor to the ceiling and close the hole. Subsequent dust storms could then have hid the feature from being visible on the surface.

Re: APOD: A Hole in Mars (2020 Mar 01)

by wildespace » Sun Mar 01, 2020 3:59 pm

SpaceCadet wrote: Sun Mar 01, 2020 12:37 pm How is martian life a possibility when there isn't any atmosphere to speak of?
Some forms of like don't require oxygen (or any atmosphere really). Thermal vents, even solid rocks. There are organisms feeding off chemical composition.

Re: APOD: A Hole in Mars (2020 Mar 01)

by saturno2 » Sun Mar 01, 2020 3:25 pm

This hole is strange

Re: APOD: A Hole in Mars (2020 Mar 01)

by Chris Peterson » Sun Mar 01, 2020 2:44 pm

SpaceCadet wrote: Sun Mar 01, 2020 12:37 pm How is martian life a possibility when there isn't any atmosphere to speak of?
Simple life doesn't require an atmosphere. Just occasionally liquid water and a source of energy.

Re: APOD: A Hole in Mars (2020 Mar 01)

by orin stepanek » Sun Mar 01, 2020 1:53 pm

marshole2r_hirise_960.jpg


It's so perfect; almost made rather than created by natural
causes! A volcano cone; or a sinkhole? :roll: 🛸

Re: APOD: A Hole in Mars (2020 Mar 01)

by smitty » Sun Mar 01, 2020 1:16 pm

Have any other similar holes been found on Mars? If so, how many?

Re: APOD: A Hole in Mars (2020 Mar 01)

by SpaceCadet » Sun Mar 01, 2020 12:37 pm

How is martian life a possibility when there isn't any atmosphere to speak of?

Re: APOD: A Hole in Mars (2020 Mar 01)

by neufer » Sun Mar 01, 2020 12:29 pm

https://www.uahirise.org/hipod/ESP_063262_1755 wrote: <<This observation was meant to examine a pit identified in a Context Camera image to see if HiRISE could resolve any details inside. In this cutout, we see the “normal” view of the HiRISE image on the left, while the right shows what happens when we try to “enhance” the brightness of the pixels in the pit.

Fortunately, HiRISE is sensitive enough to actually see things in this otherwise dark pit. Since HiRISE turned by almost 30 degrees to capture this image, we can see the rough eastern wall of the pit. The floor of the pit appears to be smooth sand and slopes down to the southeast. The hope was to determine if this was an isolated pit, or if it was a skylight into a tunnel, much like skylights in the lava tubes of Hawai’i. We can’t obviously see any tunnels in the visible walls, but they could be in the other walls that aren’t visible.>>

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