APOD: A Hole in Mars (2020 Mar 01)

[SpaceCadet]

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!

[TheArtofWalls]

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

[neufer]

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

The Great Pit of Carkoon

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<<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.">>

[Ann]

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