What would they be? for some reason it makes me think of bluer creatures

>Plant life on earth is green because the suns output peaks in the green part of the spectrum.
Oh??

Remember rhodopsin?

The green colour is from chlorophyll, absorbing red and blue but reflecting green.

A hotter star than ours would have a wider Goldilocks zone which could be interesting.

Also, a hotter star would have a Goldilocks zone further out so I am not sure if the increased radiation would be much of a problem.

>What about the panspermia hypothesis?
user said "develop" when it's clear the conditions he cites makes life in general unlikely.
Panspermia is even less plausible than abiogenesis in your scenario. Why would life adapted to a world like Earth do well on a more hostile world?

One of the theories about why nature chose a green substance for that role is because of the green sun, if they absorbed that particular wavelength it would generate too much excess heat and they would die in times of stress.

>because of the green sun
Wait, what?? Which green sun? Ours is yellow.

The argument also fails to explain why rhodopsin used to dominate photosynthesis and still is used in some algae.

Excess heat is formed when you operate too far above the work function. In theory you could make leaves like the Foveon sensor, not sure if that is already done in nature.

>Wait, what?? Which green sun? Ours is yellow.
google.com/search?q=no green stars
All yellow stars are also green, we just don't see it that way.

>would mars's atmosphere get an considerable increase in pressure? No
Actually, it would, eventually - assuming the moon didn't move. The Earth's moon, orbiting around Mars, would likely create enough gravity differential to start Mars's core spinning at a different rate than its surface again, creating a magnetic field, which would stop it leaking atmosphere, in addition to providing radiation coverage for critters, and making it geologically active again, spewing more random crap into the air.

The Earth, on the other hand, in Mars orbit, wouldn't be able to harbor life for very long, at least not without an incredible amount of human interference, likely far greater than would be possible with our current industrial levels and tech.

(Though that might still better than a roll of the dice, as who knows what atmospheric mix you'd end up with, back on 3rd orbit Mars.)

I can see how the Moon would knead Mars' core but I cannot see how that would start it spinning again.

It's already spinning - along with the rest of the planet. It's also thought to have a liquid layer, but not much of one, so it's more in sync with the planet than Earth's. A strong moon would create a spin differential between the mantle and the liquid section, as the mantle would be receiving more pull than the core, expanding it in the process. Doesn't take much of a differential to create a magnetic field, which Mars probably had when it was younger, and more geologically active.

Granted, it might take a few hundred million years, and you've only got about a billion before that area gets far too hot to be considered "habitable" zone anymore. But hey, then 4th orbit Earth starts to look better - assuming it hasn't tidally locked.

>Meanwhile colder stars' "habitable zone" is very near to the star, that results in permanent tidal lock and severe radiation from the star
Planets tend to pick up, and often perpetually maintain, billions year long spins for any number of reasons, and solar radiation is overrated, easily stopped by even modest water, which you probably need to spawn life anyways, as well as nearly any amount of dirt. The more common types of those smaller stars have a much higher propensity for rocky planets, less propensity for dangerous ort clouds, and actually have a wider habitable zone per planet, on average (at least around those few we've been able to get a good enough look at so far). And, of course, those types are about a thousand times common, and last about a hundred times as longer... So all in all, I wouldn't be so quick to dismiss them, and it may very well be that life elsewhere considers yellow stars non-starters in their own search for life. (Granted, I'm sure they certainly wouldn't bother looking this far out on the rim, given how slim the pickings are out here - unless, of course, they are neighbors.)

Our own yellow star, *barely* lasts long enough to get us this far. I mean, yes, she's got another 4 or 5 billion years left in her, but she's only one before she gets so hot that those oceans are entirely converted into atmosphere... Which kinda means we evolved just under the wire, in the grand scheme of things.

>Planets tend to pick up, and often perpetually maintain, billions year long spins for any number of reasons,
>implying we have vast knowledge of exoplanets

Come back when we've studied planets from more than just our solar system.

Well, for starters, we have lots of examples of that in our system, not just planets, but planetoids, and we kinda assume the laws of physics are the same everywhere.

...There aren't a lot of planets close enough and large enough for us to determine their day length, yes, but we have enough theories as to solar system formation, and examples around us, to come up with hundreds of reasons shit like that might happen and has happened.

...and then there's incredibly dated pic related.

Now, the samples for formation of life may number a total of one, and the mysteries surrounding it are both complex and numerous - but large spinning bodies are a considerably simpler phenomenon to predict.

>...There aren't a lot of planets close enough and large enough for us to determine their day length, yes,
Thanks for agreeing with me.

>but we have enough theories
I think you mean hypothesises. Actual theories are tested. Which is my point to begin with.

But based on current schools of thought, I think the safe bet is that most (or all) red-dwarf Goldilocks planets are tidally locked, in spite of potential loopholes.
More importantly, in relation to OP's question, while we can't rule out an Earth-like planet orbiting a red dwarf, I think it's safer to say life may well exist there despite the likely potential for a very different environment.

>I think you mean hypothesises. Actual theories are tested. Which is my point to begin with.
Fine, it's a hypothesis with a whole lotta evidence, but if you're suggesting the activity in the solar system here, isn't indicative of similar activity elsewhere, and that the basic laws of mass on that scale aren't thoroughly proven to be predictive, you're dancing on that "ya canna no nuttin about nuttin" line.

>but if you're suggesting the activity in the solar system here, isn't indicative of similar activity elsewhere
I'm not.
Are you implying our solar system contains a red dwarf with a closely orbiting planet?

>basic laws of mass on that scale aren't thoroughly proven to be predictive
The predictions lead to tidal locking.
Al best, you can suggest some other forces may overcome this in some cases, but you certainly can't claim that, in general, red-dwarf Goldilocks planets aren't tidally locked.

If we're going to get all speculative, I'd say the most likely scenario is that the standard for life in the universe involves an environment with a tidally-locked world orbiting a red dwarf.
...assuming the large number of red dwarfs offsets the handicaps that environment presents.

>The predictions lead to tidal locking.
No, not really - not much more than they do here, because shit happens here all the time, where planets and asteroids that shouldn't be spinning, are.

...There's nothing we know or have hypothesized about a red dwarf system that precludes sizable moons or catastrophic primordial collisions. Shit happens, and it doesn't take much, in space, to make shit spin.

I am puzzled by a lot of what you wrote. Do you have a background in this field?

>- not much more than they do here
Yes, more than here, ffs.
The first comparable situation that come to mind is the Earth-Moon pair, and guess what?
Remind me how many planets orbit as close to the sun as a red-dwarf Goldilocks zone?

>where planets and asteroids that shouldn't be spinning, are.
An example would help your case.
OK Saturn, what else?

>nothing we know or have hypothesized about a red dwarf system that precludes sizable moons or catastrophic primordial collisions
Sure, but there's nothing to indicate that such are the norm, not the exception.

>An example would help your case.
Really? I mean, it'd be much easier to count the things that aren't spinning in this solar system that fail to face lock with the sun, and even easier to count the things that have a spin that isn't entirely the result of the sun.

Saturn's a poor example, as it's a gas giant, and all giants spin in multiple layers. Even Uranus, which does so on its side, giving some indication of just how violent these collisions and near misses can be, considering its mass.

Even Venus isn't truly tidally locked, and it's rotation is retrograde, due to some crazy disaster in its formation. Meaning, it isn't even tidally locked due to its position, but due to a nearly equal counter reaction.

And moons seem to be the norm around planets here, and entangled gravity wells the norm among planetoids, with most of them being paired in mutual tidal locks, entirely independent of the sun - occasionally three, four, and even eight way concentric orbits. If a planet has a sizable moon, it can't be tidally locked with its star, that's just how gravity works.

The only object even close to tidally with the sun, in the entire solar system, is Mercury, and it rotates three times for every orbit, so even that planet isn't tidally locked, despite being under more direct gravitational influence of our sun than near anything else.

It takes a really ideal set of circumstances, and dumb luck, for an entire planet, during its billions of years initial formation, not to interact with another massive object in such a way as to keep it in spin for billions of years afterwards. It's never happened here, and while it might be more likely to happen at closer proximity to a smaller star, it's still damned unlikely, save maybe in the distant future, after such systems have had the chance to stabilize - but given our solar system is a third the age of the entire universe, for most of them, that'd be a long, long while from now.

nonono, original guy here, each planet keeps their own moons, forgot to clarify that

Plants are green because chlorophyll is a superior compound for photosynthesis. It's not optimal for absorbing the sun's peak spectra, but makes up for it with efficiency in red and blue.

>Ours is yellow.
from our position
go into space and its white and a little green

It's kind of like those green shirts in Star Trek, they appered gold in TV...

Not him, but it's a common Mars terraforming fantasy. Taking something like Ceres and sticking it in close orbit to create distributed stressors and free up the core. Albeit, it's a stupid one, as there are much more practical solutions, such as the artificial orbital solar powered geopoles that NASA was fantasizing about recently. On the other hand, if you could wave a magic wand and do it, I don't think it'd take as long as he describes to take effect - though like he says, dunno what kind of atmosphere you'd get without interference, it could just go full Venus on ya.

Oh, well, they're both right fucked then.

>it's an "argue about colors" episode

Don't start...

> Ours is yellow
It's white

Depends on the lighting, of course.

>from our position
Exactly. The atmosphere scatters a lot of the blue. And it is the direct lighting that the plants exploit, not what happens in space.

Same as above.

Earth would be fine because we have a sick magnetic field, Mars was habitable before its core cooled and it lost the majority of it's magnetic field. Mars is boned either way you look at it. Sure it would be able to have water because it would be closer to the sun, but because there's basically no atmosphere it would evaporate and just leave the planet. The only thing that can save Mars is a massive asteroid impact that can get the insides molten and churning again, or if we can set up some sort of artificial magnetic field.

Our definition of white is the color of sunlight, which is a combination of all the wavelengths of the visible spectrum with less blue, more yellow, and a lot more green (on a side note, that's why some lightbulbs look fucking weird, because our mind can tell that it's so shit and unnatural when it sees a bulb that produces more blue light or something)
So yes, the sun looks white to us, because that's how we define the color in the first place, but astronomically speaking, it's a green star.

>Hotter (especially blue) stars don't have the lifespan for any life to develop on nearby planets
source: my ass

Source: literally anywhere that knows anything in the field

A magnetic field ain't gonna help you when the oceans freeze solid.

Your ass is huge.

Mars had liquid water on it when it's atmosphere was still a thing, also water can get below freezing temperatures and stay liquid, especially with all the salt, see: Arctic/Antarctic oceans. Oceans won't freeze.

Solar system was younger and hotter at the time. You ain't turning the sun down x2.25 times without drastic consequences.

Interesting little blog on the subject here:
blogs.scientificamerican.com/observations/what-would-happen-if-earth-and-mars-switched-places/

The temperature changes are rather obvious... What is less obvious (judging by the responses), is the gravitational skew it causes throughout the entire solar system. Seems this system settled into this formation very early on, and if you suddenly change the masses of the various orbits, they pull on each other in crazy ways.

>Although none of the inner planets gets flung out of the solar system within the first 10 million years, all undergo large variations in their orbital distances. On occasion, Mars dips inward to become the second rock from the sun.

Stranger, is what happens if you magic wand Mercury away:

>To speed things up, she tried ignoring the planet Mercury—standard practice in perturbative calculations, on the assumption that Mercury is so piddling that its gravity is immaterial. Not in this case, though. Without Mercury, the other three inner planets went haywire in a few million years. Mars shot off into deep space.

Granted, this all takes quite a bit of time - but, suffice to say, be careful when waving that magic wand, things are in many ways, more fragile than we think, yet more durable in others.

The planets were cooler billions of years ago because every star's luminosity increases as it ages. The sun now is hotter than it was in the past and in a few hundred million years it will be hot enough to trigger a runaway greenhouse effect on Earth so we will end up like Venus without human intervention.

>went into universe sandbox quickly to check out
>put earth on mars's orbit
>it froze over

>put earth slightly further away from it's real orbit
>it froze over again

but why did it freeze again the second time? it was so close to the normal one

No, everything in the system was sitting in a boiling cauldron of plasma billions of years ago. Most of the inner planets were a semi-liquid state in their earlier years, everything was irradiated to hell, and every other thing was colliding with every other thing in a hyper excited state, because most young solar systems look like pic related.

It took a long time for the hot gasses, and later, loose molten rocks that made up the protoplanetary disk that surrounded the sun to collect, cool, and settle into place, but everything in this solar system was magnitudes hotter in the distant past, everything in it being, basically, forged in fire, and that all took quite some time to cool.

...

...

I managed to get a comfy 2.5~3.5°C average global temperature, had to put earth just a little further out than it currently gets at apogee

the question is, did I fuck over everyone by doing this?

You relocated a few million sim-farmers, caused mass sim-emigration, and probably a few sim resource wars, but sim humanity will go on.

>"Quit that!" - Sincerely, Sim Humanity.

Someone should test the stability of an extra Mars sized planet between the orbits of Mars/Earth, and Earth/Venus.

0%

>tfw no qt double planet

(Yes I know the angle of the Sun is fucked up. Stop bullying me)