Extraterrestrial life; what could it look like?

[Cabbink]

As the title suggests, I would like to see some ideas of your perspective of extraterrestrial life, from floating cloud like creatures to little fish. 

@ProtoJeb21 @Spaceception @NickRoss120 @cratercracker @Adstriduum

Edited August 2, 2017 by Cabbink

[Just Jim]

Small.... green... maybe a meter or so tall... big eyes... stubby arms and legs  

(sorry, couldn't resist... lol)

Edited August 2, 2017 by Just Jim

[Bill Phil]

It'll look like what it looks like. 

Although I am partial to the design of the Elder Things...

Even so, I think there's not much to gain from trying to come up with alien appearances...

I do remember a scene from 2001: A Space Odyssey (the book) where the characters discussed what the optimum design for an intelligent being is. I think it was four way symmetry around a cone with eyes and manipulators in four directions.

[razark]

What couldn't it look like?

 

[Spaceception]

Ugh, I can't answer tonight, but I'll write something down tomorrow. 

[cubinator]

If it's on a Super-Earth, maybe something like beefy starfish, with either lots of legs or a snail-like foot and a low center of mass.

An Earth-like world with low gravity might yield some really interesting shapes for creatures, as they don't need as much structural stability.

1 minute ago, Bill Phil said:

I do remember a scene from 2001: A Space Odyssey (the book) where the characters discussed what the optimum design for an intelligent being is. I think it was four way symmetry around a cone with eyes and manipulators in four directions.

That sounds like something I've seen somewhere before...

[Spaceception]

Also, shouldn't this be in sci/space?

[Cabbink]

6 minutes ago, Spaceception said:

Also, shouldn't this be in sci/space?

Ah. Thanks.

[kerbiloid]

13 hours ago, razark said:

What couldn't it look like?

Spoiler

 

13 hours ago, Bill Phil said:

optimum design for an intelligent being is. I think it was four way symmetry around a cone with eyes and manipulators in four directions.

True intelligent being needs one eye to watch display and one tentacle to tap and slide.
Those four/four are just servants.

[Tex_NL]

Obviously the exact environment dictates the details but there are a few things any advanced life form needs to have no matterwhat.
It needs to be able to sense its environment: eyes, ears, etc. or something equivalent. Probably two or more of each to sense depth and direction. But it won't be dozens as this would require too much energy to maintain. And it will have its eyes high up on its body looking forward.
It will need to interact with and move through its environment: it will need limbs and claws. Two arms and two legs would probably the required minimum for manipulation and stability but it can of course be more. Same with the eyes too many libs will be inefficient.
Any 'active' creature will most likely be exothermic so it needs to feed and probably breath. It needs a mount and an anus. But a single part can fulfil multiple rolls.
It MUST obey the laws of physics. Any aquatic (or any other liquid) creature will probably look similar to a fish. Any flying creature will need to be light weight for its size and needs wings or a 'balloon'. Not because of a biased human viewpoint but because of physics.

Similar environmental circumstances will lead evolution in similar directions. It's called convergent evolution.

An alien visitor that looks vaguely humanoid is therefore not all that outlandish.

Edited August 2, 2017 by Tex_NL

[NickRoss120]

@Cabbink Basically, aliens can be anything, sort of. You can get a good idea of what some extraterrestrials look like from the documentary Alien Planet, It's particularly interesting. For the ones that are intelligent like us? They could be space dolphins or space mantids for all I know.

[RoadRunnerAerospace]

They would look very.... Interesting

[kerbiloid]

What does the terrestrial life look like?

Spoiler

Exact part shapes and sizes may vary from species to species.

What does the extraterrestrial life look like?

Spoiler

Exact part shapes and sizes may vary from species to species.

Edited August 2, 2017 by kerbiloid

[Spaceception]

Alright here's my take.

Lower gravity worlds .8g <

Thin atmosphere .5 <: Life in these planets would likely be small and fragile, since there's a thin atmosphere, it would probably be harder to get energy. Think water-bears, ground crawler insects, and short plants.

Thick atmosphere 2atm>:  This is where things get fun, a thin atmosphere and weaker gravity means flying creatures would be much more common, there would likely be more huge flying creatures, dragons without firebreathing perhaps?

For planets with atmospheres about as dense as ours, they would have an easier time flying, so you could also expect lots of aerial aliens. 

Higher gravity worlds 1.3g>

Thin atmosphere: The life on these planets would be short, dense, and stocky, you'd be pretty hard pressed to find anything decently tall, flying creatures would probably be very hard if not impossible. 

Thick atmosphere: Here, you could probably find aliens that are taller, maybe even aerial ones, but they would be smaller. Marine life may be more common. But it woukd still be stockier. 

For planets with atmospheres about as dense as ours, I'd say you'd mostly find more Marine life, land creatures would depend on surface conditions however.

This is for aliens with habitability similar to Earth's, and I'm no biologist, but this is what I think would be on these planets.

Edited August 3, 2017 by Spaceception

[Green Baron]

Who knows ?

Won't get into details, costs too much time.

Earth's evolution has developed organisms weighing in the hundreds of tons per individual as well as sedimentary rock building microorganisms or flyers with a wingspan of 10m (33feet) or those with just a few cm. Gravity, atmospheric/oceanic composition, temperature were the same (+/-a few K or percent oxygen) in that time.

There must be other mechanisms in excess of those we could probably watch in the future on et planets that drive a proper evolution ;-)

Edit: though i admit it is fun to speculate :-)

Edited August 3, 2017 by Green Baron

[NSEP]

Every shape and size you can litterly think of, everything from something like growing crystals, to gaint penguins the size of Mountians.

It really depends on the planet/climate they live on. I might make a chart of some sort.

[Spaceception]

3 minutes ago, NSEP said:

Every shape and size you can litterly think of, everything from something like growing crystals, to gaint penguins the size of Mountians.

It really depends on the planet/climate they live on. I might make a chart of some sort.

That last one wouldn't be true, check out Film theories video on ant-man

[NSEP]

On 02/08/2017 at 4:21 AM, razark said:

What couldn't it look like?

 

Like a house with nameplate, interioir and furniture with plumbing and everything.

I mean, maybe it could but... i dunno.

1 minute ago, Spaceception said:

That last one wouldn't be true, check out Film theories video on ant-man

I know that video, you know we are talking other planets here. Im pretty sure that ocean planets with low gravity can sustain Hugh Mungus creatures, or at least bigger than what we have here.

[Spaceception]

6 minutes ago, NSEP said:

Like a house with nameplate, interioir and furniture with plumbing and everything.

I mean, maybe it could but... i dunno.

I know that video, you know we are talking other planets here. Im pretty sure that ocean planets with low gravity can sustain Hugh Mungus creatures, or at least bigger than what we have here.

Well, yeah (And I think I talked about the wrong video, that Film theory one was the first one that popped into my head) but you know that fake fact about ants (Where I got the thought from) if you increase its size dramatically, it wouldn't be able to support its own weight because of uh, the square cube law I think? Anyway, it would have to have really really really thick legs to support itself, and they were talking about ants the size of houses, I don't even know how a Penguin the size of a mountain would work. Not to mention it would die rather quickly due to needing a lot of food (That's the understatement of the year), and other limitations. While that would be cool, and kinda funny on paper, it wouldn't be possible in real life.

Oh, and King kong wouldn't be possible either because of that.

[NSEP]

6 minutes ago, Spaceception said:

Well, yeah (And I think I talked about the wrong video, that Film theory one was the first one that popped into my head) but you know that fake fact about ants (Where I got the thought from) if you increase its size dramatically, it wouldn't be able to support its own weight because of uh, the square cube law I think? Anyway, it would have to have really really really thick legs to support itself, and they were talking about ants the size of houses, I don't even know how a Penguin the size of a mountain would work. Not to mention it would die rather quickly due to needing a lot of food (That's the understatement of the year), and other limitations. While that would be cool, and kinda funny on paper, it wouldn't be possible in real life.

Oh, and King kong wouldn't be possible either because of that.

Penguins with a higher percentage of water in body weight, sitting with its whole body on the surface while being lazy like a sloth and feeding of coral reefs or underwater forests sounds a bit more plausible. Ok maybe its not a penguin anymore. 

 

[munlander1]

I don't think we can really speculate, since so much relies on evolution. A lot of things look similar to us because we are related. 

[Urses]

4 minutes ago, munlander1 said:

I don't think we can really speculate, since so much relies on evolution. A lot of things look similar to us because we are related. 

Which crazy evolutionary mechanism invented Spiders (in the name of sience who need 8 eyes and legs?) or snakes (big angry and/or poisonus ropes?)

On other hand substitute carbon with silizium on a "little" hotter planet and you get a maybe earth alike but more resistant lifeform...

The big problem would be more not to Encounter a exteristrial lifeform but to recognize this one as one?

[Vanamonde]

Some sciency type stuff is going to come up in this thread, and so it has been moved to Science and Spaceflight. 

[magnemoe]

6 hours ago, Spaceception said:

Alright here's my take.

Lower gravity worlds .8g <

Thin atmosphere .5 <: Life in these planets would likely be small and fragile, since there's a thin atmosphere, it would probably be harder to get energy. Think water-bears, ground crawler insects, and short plants.

Thick atmosphere 2atm>:  This is where things get fun, a thin atmosphere and weaker gravity means flying creatures would be much more common, there would likely be more huge flying creatures, dragons without firebreathing perhaps?

For planets with atmospheres about as dense as ours, they would have an easier time flying, so you could also expect lots of aerial aliens. 

Higher gravity worlds 1.3g>

Thin atmosphere: The life on these planets would be short, dense, and stocky, you'd be pretty hard pressed to find anything decently tall, flying creatures would probably be very hard if not impossible. 

Thick atmosphere: Here, you could probably find aliens that are taller, maybe even aerial ones, but they would be smaller. Marine life may be more common. But it woukd still be stockier. 

For planets with atmospheres about as dense as ours, I'd say you'd mostly find more Marine life, land creatures would depend on surface conditions however.

This is for aliens with habitability similar to Earth's, and I'm no biologist, but this is what I think would be on these planets.

High air pressure and you get large flying creatures, lower gravity is less important for this, You would be unlikely to find earth like planets with 2g gravity, and 1.5g would just feel like being overweight. yes you would have stronger legs and max size of animals would go down. 
Back to flying, this will probably help intelligence, birds are very smart for their brain size. Earth has an maximum size for flying and non flying birds don't need to be smart. 
Smart only start to pay back then you get smart enough for tribal cultures and / or tool use.
 

[magnemoe]

On 2.8.2017 at 6:44 PM, Tex_NL said:

Obviously the exact environment dictates the details but there are a few things any advanced life form needs to have no matterwhat.
It needs to be able to sense its environment: eyes, ears, etc. or something equivalent. Probably two or more of each to sense depth and direction. But it won't be dozens as this would require too much energy to maintain. And it will have its eyes high up on its body looking forward.
It will need to interact with and move through its environment: it will need limbs and claws. Two arms and two legs would probably the required minimum for manipulation and stability but it can of course be more. Same with the eyes too many libs will be inefficient.
Any 'active' creature will most likely be exothermic so it needs to feed and probably breath. It needs a mount and an anus. But a single part can fulfil multiple rolls.
It MUST obey the laws of physics. Any aquatic (or any other liquid) creature will probably look similar to a fish. Any flying creature will need to be light weight for its size and needs wings or a 'balloon'. Not because of a biased human viewpoint but because of physics.

Similar environmental circumstances will lead evolution in similar directions. It's called convergent evolution.

An alien visitor that looks vaguely humanoid is therefore not all that outlandish.

Yes and this is important, you get all sort of strange animals and plants but in some niches you get the same pattern. 
First all the stages has to work and you have predators, also an intelligent species will be fairly long lived and has to teach their kids a lot.
You will have an head with sensors, the brain and probably mouth. you want short communication lag and having the mouth in head makes sense as you have to rotate it anyway. 
I see 3 probable body plans, first in the human one, two arms, legs and upright, second is the dinosaur one with an heavy tail to counter balance, this should work pretty much as well. 
Last in centaur with 6 limbs probably less likely but larger chance of getting arms. 

Oxygen breeder, warm blooded unless large, you want an anus as you need plenty of food and not low energy plant food either, meat or high value plant food like nuts, fruits or seeds. 
Breathing might be separate from mouth. 

No it will probably not look like an human, imagine an predator kangaroo with an fur who look like moss and can change color, the kids suck the mothers blood rather than milk. It will have an larger brain, ears will not be on top of head but at sides. Jaw will be weaker as not much room for strong jaw muscles the because of brain take too much room and no need as it has tools. 

Smaller creatures has more flexibility as they don't have all the restrains.