Problem Gliese 581 Planetary System

[Wishbone]

The question to resident experts: are there any reasonably fast, open-access, low-resolution atmospheric/oceanic general circulation models that may provide a quick picture of climate given planetary parameters (solar constant, composition of the atmosphere, rotation rate, period, obliquity)?

 

[donatelo200]

Kelvin confuses the heck out of me, so I use the temperature measurement system that's shifted by 273.15 degrees...

I agree though, I absolutely cannot stand farenheit. :uhh:

Agreed. Who ever made farenhiet must have be on something.:focus: Celcius make sense but i'm used to farenheit so that what i use.......................:facepalm:

 

[T.Neo]

Celsius. It's easier to learn and it uses the freezing and boiling point of water as reference points, so it's quite intuitive.

Human body temperature isn't something you come across often, and 100 farenheit isn't even human body temperature... :facepalm:

 

[fsci123]

According to my understanding...
GL581 is 7 billlion years old... Added with the effect of a lack of magnetic field on most bodies... Heat will not evenly spread to both sides. And it will also lack large mountains from gravity... but in theory gl581d will be in resonance like mercury... I think most of us have to deal with the problem of glaciers on one side and a dessert on the other(that which i have solved)

 

[T.Neo]

No high mountains? No. There'll definitely be mountains, even if topography is muted compared to that of Earth or Mars.

The nearside won't be a desert, if there's ocean there (and there probably will be, since the planet is so large it's bound to have large oceans) it'll be quite wet, and on the sunward side of the terminator temperatures will be quite Earthlike. Only once you get close to the sunward pole do things really start to become hot.

While I can see evaporation lowering sea levels at the sunward point, I don't see any way that it could carve through kilometers of water...

 

[RisingFury]

The tempuratures i have shown are just the way i set up gliese 581 g in my addon. Thats just the way i imagend it. The real planet if it exists could be totally different. We don't know what goes on on this planet. So untill we get a clear photograph of the planet we don't know it's climate.

By now you should have known that almost no data in modern astrophysics comes from pretty pictures.

 

[fsci123]

No high mountains? No. There'll definitely be mountains, even if topography is muted compared to that of Earth or Mars.

The nearside won't be a desert, if there's ocean there (and there probably will be, since the planet is so large it's bound to have large oceans) it'll be quite wet, and on the sunward side of the terminator temperatures will be quite Earthlike. Only once you get close to the sunward pole do things really start to become hot.

While I can see evaporation lowering sea levels at the sunward point, I don't see any way that it could carve through kilometers of water...

When i mean dessert i mean like no rain...
It would have a hypercane on the near side and it will be raining on the far side... The rain will turn into ice and will melt back into rivers that flow back to the near side...

 

[T.Neo]

By now you should have known that almost no data in modern astrophysics comes from pretty pictures.

Define "pretty pictures"... I think quite a lot of data could be regarded as "pretty".

Maybe it's just me... :shifty:

When i mean dessert i mean like no rain...
It would have a hypercane on the near side and it will be raining on the far side... The rain will turn into ice and will melt back into rivers that flow back to the near side...

I doubt it. A good deal of the nearside will be cool enough for rain, and my personal hunch is that most of the evaporated moisture from the sunward poles will condense and fall as rain before the terminator, making precipitation on the farside minimal.

There aren't going to be any rivers on the farside surface, it'll all be frozen solid. Most reintroduction of water to the nearside will be by glacial action.

 

[Wishbone]

http://www.shodor.org/master/environmental/general/energy/energy.html

 

[Axel]

A question, why you all invest so mutch work in this system? This system is maybe of astronomical interest, but not for space travel, what we do in orbiter. There is no planet which enables a human surface mission or settling. The masses are to big for walking, the smallest with moderate temperatures has 5 earth masses(!). Only very strong men could maybe walk there, but its not very healthy for the body. And i try to imagine what for a gigantic rocket/spaceship we would need, to go back to space from it.
So orbital bases would be the only realistic bases there.
So create better systems with planets/moons in about earth size, smaller or maybe a little bigger, around gas giants in habitable zones or alone, fictive or not.

 

[Maquis]

Hmm, I wonder if You can point me into calculations (I mean equations) for greenhouse effect in planetary bodies? The one I had was very simple and generated huge errors.

 

[donatelo200]

A question, why you all invest so mutch work in this system? This system is maybe of astronomical interest, but not for space travel, what we do in orbiter. There is no planet which enables a human surface mission or settling. The masses are to big for walking, the smallest with moderate temperatures has 5 earth masses(!). Only very strong men could maybe walk there, but its not very healthy for the body. And i try to imagine what for a gigantic rocket/spaceship we would need, to go back to space from it.
So orbital bases would be the only realistic bases there.
So create better systems with planets/moons in about earth size, smaller or maybe a little bigger, around gas giants in habitable zones or alone, fictive or not.

Well it's more of a challenge to land on planet over twice the mass of Earth. (makes life more interesting) Even though these planets are over 3x Earths mass it dosn't mean you can't walk on them. The human body can withstand 10gs and the surface gravitys on these planets will range from 1.4 to a little over 2 gs. So you could walk an these planets it would just take a littel more effort.

 

[T.Neo]

A question, why you all invest so mutch work in this system? This system is maybe of astronomical interest, but not for space travel, what we do in orbiter. There is no planet which enables a human surface mission or settling. The masses are to big for walking, the smallest with moderate temperatures has 5 earth masses(!). Only very strong men could maybe walk there, but its not very healthy for the body.

Of course it is of interest to space travel. It is relatively close, though probably not in range of the first interstellar missions (~20 light years)

The gravity is not an issue- the (probable) lower density of planets c and d mean that surface gravity should be acceptable. That isn't the problem.

The problem is that Gliese 581 c is in all probability a super-Venus, a planet with a runaway greenhouse effect. Considering that it probably has a higher atmospheric pressure at the surface than even Venus, walking on the surface would be entirely impractical. Gliese 581 d, is believed to be a world-ocean. So no walking there, obviously, even if you were, I dunno... swimming there, or floating there, or something.

And i try to imagine what for a gigantic rocket/spaceship we would need, to go back to space from it.

Easy. Just use nuclear power. :thumbup:

If you perform interstellar travel, you can use nuclear propulsion to lift off from say, Gliese 581 d.

So orbital bases would be the only realistic bases there.
So create better systems with planets/moons in about earth size, smaller or maybe a little bigger, around gas giants in habitable zones or alone, fictive or not.

Why? What's wrong with orbital bases, or even asteroid bases? Orbiter is about flying, not landing... unfortunately if there is no planet to land on here, there could still be asteroids or suchlike.

There's nothing wrong with a fictional system, but real systems are many times better, because, well, they're real. There's nothing quite like flying around a system that actually exists, many light years away.

And you can't always get it right. My Mu Arae system already has a moon that is many times bigger than what could form, if you support the formation theory by Canup and Ward...

 

[Axel]

The problem is that Gliese 581 c is in all probability a super-Venus, a planet with a runaway greenhouse effect. Considering that it probably has a higher atmospheric pressure at the surface than even Venus, walking on the surface would be entirely impractical. Gliese 581 d, is believed to be a world-ocean. So no walking there, obviously, even if you were, I dunno... swimming there, or floating there, or something.

So how can it be intresting for a human surface landing? It isn't!

The gravity is not an issue- the (probable) lower density of planets c and d mean that surface gravity should be acceptable. That isn't the problem.

Planets with about 1,5x d of earth have 4-5 earth masses and a gravitity of about 2 times of earth. I dont know, if its possible to walk there easy?
My weight is 96kg, thats not mutch because im tall, if im 192kg, its possible to walk there? There are people in the world with 192kg, but they have big problems to walk. I think to walk at 2x earth gravity conditions, we need extrem body training and/or a special space suit, with servo motors.

Why? What's wrong with orbital bases, or even asteroid bases? Orbiter is about flying, not landing... unfortunately if there is no planet to land on here, there could still be asteroids or suchlike.

Why should an astronaut take the big hard challenge to fly 20 light years to visit or land on an asteroid or docking to an orbital base? Thats crazy sorry. This system is only intresting for unmanned missions, interstellar probes ect.

 

[T.Neo]

So how can it be intresting for a human surface landing? It isn't!

Wow... that is a pretty bold statement. :uhh:

Maybe some people find it interesting, even if you (or I) do not.

Planets with about 1,5x d of earth have 4-5 earth masses and a gravitity of about 2 times of earth. I dont know, if its possible to walk there easy?

1.5 times the density of Earth?

No no, the density will be lower, not higher. This is because larger bodies accrete more light elements. For example, Uranus is 14.5 time the mass of Earth, but has only 88% the gravity, because it is far less dense.

A 7 Earth mass planet with the density of Mars has a surface gravity of 1.53 G. You will weigh "only" 147 kg. I am not sure how obese a person would have to be to compare to that, but I'd imagine that there are quite a few and they can walk, even if they have difficulties.

A powered exoskeleton is not that big of a deal, if you can build an interstellar spacecraft.

Why should an astronaut take the big hard challenge to fly 20 light years to visit or land on an asteroid or docking to an orbital base? Thats crazy sorry. This system is only intresting for unmanned missions, interstellar probes ect.

Yeah... you may think that, but other people might not. People, for example, that might want to research any organisms living in the oceans of GLiese 581 d...

It might not warrant a mission in reality, but in Orbiter, why not? We do not have time constraints like that to worry about.

 

[jedidia]

So create better systems with planets/moons in about earth size, smaller or maybe a little bigger, around gas giants in habitable zones or alone, fictive or not.

Define "better". Orbiter has always been more about realism and accuracy than about user friendlyness, you know. In this context "more accurate" might easily qualify as "better" than "fun, but totally unbelieavable".

 

[Axel]

@T.Neo
I mean with "d" the diameter, i thought you ment it.

@Jedidia
I do like more fictional but maybe possible systems with really earthlike planets, than famous systems like Gliese581 with unsuitable planets.
Very good examples and FUNNY systems are 55Cancri and Ups Andromedae.
But i dont like it when people insert habitable moons around earth or between mars and jupiter, which is really unrealistic.
Fun yes, but please with a part of realism alltimes.

 

[fsci123]

IN reality, nuclear propulsion wont get you off any body 75% of earth....
DUE to the nature of traveling to a 1 mile asteroid or orbiting a lone star will be more exciting than colonizing every body in the system.

 

[T.Neo]

than famous systems like Gliese581 with unsuitable planets.

Unsuitable planets? What unsuitable planets?

Y'know, I live in a system that has Venus, a terrestrial planet unfortunately made "unsuitable" by a thick, hot atmosphere, and several gas giants that cannot be landed on including Jupiter, which has lethal radiation belts...

IN reality, nuclear propulsion wont get you off any body 75% of earth....

How did you come by this number?

DUE to the nature of traveling to a 1 mile asteroid or orbiting a lone star will be more exciting than colonizing every body in the system.

A lone star and even a 1.6 kilometer asteroid are still pretty boring... at least Gliese 581 has some pretty interesting planets to study.

 

[Axel]

Y'know, I live in a system that has Venus, a terrestrial planet unfortunately made "unsuitable" by a thick, hot atmosphere, and several gas giants that cannot be landed on including Jupiter, which has lethal radiation belts...

beside earth,moon,mars,titan and a innumerable number of moons, yeah you are right, our system is really unsuitable for manned space missions.
You should go very fast to Gliese581 for a nice roasting or swiming :lol::lol::lol:.