Superhabitable planets

[Spaceception]

So Superhabitable planets are planets that are more Earth-like than Earth, their characteristics are:

They orbit either a M or K type star (For their long life's)

They have a mass about 2 Earths (Because more shallow oceans from stronger gravity means more biodiversity, plus it's the ideal size for plate tectonics)

They're near the center of the habitable zone (So they're in the habitable zone longer as their parent star ages)

They have a temperature of 25 c (The ideal temperature for plant life as we know it)

Looking at all of these, Kepler 442b and GJ 667cf may be candidates for being a Superhabitable planet because they fill in 3 out of 4 requirements, I bet you could figure out the one they haven't met

Also, overall, they'll last much longer too, their parent star will last much longer than the Sun, giving the planet a lot of time to have life evolve, and the planet's size means it can protect itself from solar/cosmic radiation much longer than a Earth-sized planet can, which is also a big plus.

So what do you guys think about the possibility's of Superhabitable planets?

 

Edited February 8, 2016 by Spaceception

[Bill Phil]

I don't think shallower oceans help biodiversity. They help biomass, but not diversity.

[Spaceception]

50 minutes ago, Bill Phil said:

I don't think shallower oceans help biodiversity. They help biomass, but not diversity.

Quote from the wiki article:

The average depth of the oceans also affect the habitability of a planet. The shallow areas of the sea, given the amount of light they receive, usually more comfortable for aquatic species, so it is likely that exoplanets with a lower average depth more suitable for life. The more massive than Earth exoplanets tend to have a more regular surface effect of gravity, which can mean a shallower ocean basins. On the other hand, the planets with less water than Earth are less likely to present a greenhouse wild if they are in the inner ends of the habitable zone and is less likely suffering from a global glaciation if they belong to the external border.

Reference

Edited February 8, 2016 by Spaceception

[fredinno]

59 minutes ago, Spaceception said:

So Superhabitable planets are planets that are more Earth-like than Earth, their characteristics are:

They orbit either a M or K type star (For their long life's)

They have a mass about 2 Earths (Because more shallow oceans from stronger gravity means more biodiversity, plus it's the ideal size for plate tectonics)

They're near the center of the habitable zone (So they're in the habitable zone longer as their parent star ages)

They have a temperature of 25 c (The ideal temperature for plant life)

Looking at all of these, Kepler 442b and GJ 667cf may be candidates for being a Superhabitable planet.

So what do you guys think about the possibility's of Superhabitable planets?

 

M types can be bad due to the fact that red dwarfs are more dangerous to be around, and bring the danger of tidal locking.

um, wouldn't one near the edge of the habitable zone last even longer in it?

The temperature of 25 C would not always be constant in terms of climate- ice ages, and the habitable zone moving would increase/decrease the average temperature.

And why would a higher-gravity body have shallower oceans?

[Spaceception]

5 minutes ago, fredinno said:

M types can be bad due to the fact that red dwarfs are more dangerous to be around, and bring the danger of tidal locking.

um, wouldn't one near the edge of the habitable zone last even longer in it?

The temperature of 25 C would not always be constant in terms of climate- ice ages, and the habitable zone moving would increase/decrease the average temperature.

And why would a higher-gravity body have shallower oceans?

Higher mass/brighter M dwarfs (Like Lalande 21185)  would be big enough that planets in the HZ would have minimum orbital periods of 50 days, and maximum orbital periods of 140 days (Look at Kepler 186f) Which could be the lower limit (I'm guessing here!) for planets around red dwarfs to have day/night cycles without much help.

Planets in the middle of the HZ would stay in it longer as the star ages and brightens.

I know, but that's the characteristics of a Superhabitable planet.

The higher gravity would spread the water around more.

[Bill Phil]

But then all of the life is shallow water life, which can be diverse, but isn't guaranteed to be. That's why I said it's good for biomass, since there's more things that are alive, but there's no gaurantee that it's more diverse.

[AngelLestat]

2 hours ago, Spaceception said:

They have a mass about 2 Earths (Because more shallow oceans from stronger gravity means more biodiversity, plus it's the ideal size for plate tectonics)

They're near the center of the habitable zone (So they're in the habitable zone longer as their parent star ages)

They have a temperature of 25 c (The ideal temperature for plant life)

Habitable zone as they called.. is pointless to have a minimun idea on the planet temperature.
The most important to know the planet's temperature is its atmosphere, which we know nothing.

It can be far as jupiter or almost as close like mercury and have  very similar human conditions.
2 earth mass means extra gravity..  extra force to to trap gases. This might trigger a greenhouse effect without end.

[Findthepin1]

Are we capable of detecting the atmosphere on one of the two planets mentioned in the OP?

[Streetwind]

5 hours ago, Bill Phil said:

But then all of the life is shallow water life, which can be diverse, but isn't guaranteed to be. That's why I said it's good for biomass, since there's more things that are alive, but there's no gaurantee that it's more diverse.

Yeah, this. If one takes just a really brief look at our own deep ocean reaches, one will find that there's life literally everywhere. Life specifically evolved and adapted to an environment without light, which lives exclusively off of energy provided by geothermal vents and food provided by the dead biomass of higher-up marine life that silently falls onto the oceanfloor like snow in absolute blackness. Life that has some of the most absurd and ugly shapes seen anywhere on the planet, since physical appearance literally plays no role; and simultaneously, life that produces the most impressive, beautiful and pervasive bioluminescence found anywhere on Earth. Tens of thousands of species dwell exclusively down there, and we know less about them than we know about the solar system.

So yeah, I don't buy the claim in that article. It only goes to show, time and time again: wikipedia is not a primary source.

[Scotius]

For the same reason we don't want a smooth, uniform cueball. For maximum diversity we'd need swamps, rainforests, mountains, deserts, seashores and everything inbetween. Something like...Earth Then again - we are talking about life as we know it. Alien life forms probably will have wildly different demands for their optimal environment.

[Spaceception]

7 hours ago, Findthepin1 said:

Are we capable of detecting the atmosphere on one of the two planets mentioned in the OP?

Kepler 442b is 1200 ly away, so no, not anytime soon, but GJ 667cf (Which, unfortunately is unconfirmed) is 24 ly away, so we should in the next 20 years.

[Spaceception]

8 hours ago, AngelLestat said:

Habitable zone as they called.. is pointless to have a minimun idea on the planet temperature.
The most important to know the planet's temperature is its atmosphere, which we know nothing.

It can be far as jupiter or almost as close like mercury and have  very similar human conditions.
2 earth mass means extra gravity..  extra force to to trap gases. This might trigger a greenhouse effect without end.

If we're talking about planets more habitable than Earth, it'll need to be in the HZ because of light, and temperature, if we're too close, we might survive but the temperature would be much higher than Earths, and it wouldn't be considered 'Superhabitable' and if it's too cold, we would need extremely good habitat modules for heat and extremely good clothes, and it wouldn't be considered 'Superhabitable".

if a planet has 2x the Earths mass, the gravity would be 30% higher than Earths, and yes, it would trap more gases, but depending on where it's  at in the HZ, it might be just right.

[magnemoe]

10 hours ago, Bill Phil said:

But then all of the life is shallow water life, which can be diverse, but isn't guaranteed to be. That's why I said it's good for biomass, since there's more things that are alive, but there's no gaurantee that it's more diverse.

If you want high biomass you want an warm planet with shallow seas and lots of small continents with lots of shorelines.
All the small continents also helps with biodiversity, to get very high biodiversity reduce the amount of water so you get multiple seas surrounded by land. This will differentiate life in seas a lot and also probably differentiate that climb up on land. 
High gravity has some downsides in less large animals and its harder to use forelegs as arms and walk upright. 

[AngelLestat]

2 hours ago, Spaceception said:

If we're talking about planets more habitable than Earth, it'll need to be in the HZ because of light, and temperature, if we're too close, we might survive but the temperature would be much higher than Earths, and it wouldn't be considered 'Superhabitable' and if it's too cold, we would need extremely good habitat modules for heat and extremely good clothes, and it wouldn't be considered 'Superhabitable".

if a planet has 2x the Earths mass, the gravity would be 30% higher than Earths, and yes, it would trap more gases, but depending on where it's  at in the HZ, it might be just right.

No, it is all about the atmosphere..  the planet distance is secondary..
Greenhouse gases can change the temperature but a huge amount. Also the planet albedo can reflect a huge % of the light before it reach the surface.

You can have a very close planet to its star with high reflectivity at cloud level and no greenhouses gases and the temperature will be perfect.
You can have a planet very far, with a lot of water vapour and other greenhouses gases with an atmosphere of 10 Bar and you will have temperatures as earth in the surface.

Venus reflect the 72% of the light that it gets.. is light that does not contribute to the planet temperature.  But due its huge greenhouse case, it has 470c in its surface..

These are some of the effect that I can think off that influence in the planet temperature.
Atmosphere mass, atmosphere composition, tidal lock planet's (these may have a range of locations where the temperature is perfect), oceans to regulate the heat,  your location on the planet (poles, equator, terrain that generates micro weather, etc), radioactive heavy elements and geology, tidal heat due another body, magnetic fields, distance to the star, etc.

Edited February 8, 2016 by AngelLestat

[Spaceception]

34 minutes ago, AngelLestat said:

No, it is all about the atmosphere..  the planet distance is secondary..
Greenhouse gases can change the temperature but a huge amount. Also the planet albedo can reflect a huge % of the light before it reach the surface.

You can have a very close planet to its star with high reflectivity at cloud level and no greenhouses gases and the temperature will be perfect.
You can have a planet very far, with a lot of water vapour and other greenhouses gases with an atmosphere of 10 Bar and you will have temperatures as earth in the surface.

Venus reflect the 72% of the light that it gets.. is light that does not contribute to the planet temperature.  But due its huge greenhouse case, it has 470c in its surface..

These are some of the effect that I can think off that influence in the planet temperature.
Atmosphere mass, atmosphere composition, tidal lock planet's (these may have a range of locations where the temperature is perfect), oceans to regulate the heat,  your location on the planet (poles, equator, terrain that generates micro weather, etc), radioactive heavy elements and geology, tidal heat due another body, magnetic fields, distance to the star, etc.

Good points, I do agree that the HZ isn't a firm 'If you're not in here, you can't be warm' type thing, it's just a baseline, but having a planet with a temperature of 25 c, liquid water, and life, while it's well outside of the inner HZ is extremely unlikely, as is finding a planet well outside of the outer HZ (Probably more likely, but not much) with an average temperature of 25 c. What a Superhabitable planet has, is that it's inside of the HZ, it's not guaranteed to have warm temperatures, liquid water, and life, yes, but it's a good start, and it's much more likely than a planet too close or too far from it's parent star. There are a lot of restrictions for planets too close and too far from their parent stars' to have "Just right" everything's, so it's extremely unlikely that we'll find a Superhabitable planet out where Jupiter or Mercury is for example.

[Shpaget]

15 hours ago, Spaceception said:

So Superhabitable planets are planets that are more Earth-like than Earth

Does not compute.

While I agree that more shoreline would offer more room for a very important part of evolution, deep oceans are just as important.

[sevenperforce]

More gravity means a thicker atmosphere, which means biological flight actually becomes easier since you have more reaction mass to work with. Floating sky whales, anyone?

[Scotius]

Uh, no. Thanks. I prefer to not live in danger of being hit by a piece of whale excrement falling from several hundreds of meters in 2 G environment

[Spaceception]

14 minutes ago, Scotius said:

Uh, no. Thanks. I prefer to not live in danger of being hit by a piece of whale excrement falling from several hundreds of meters in 2 G environment

1.3 g, The mass would be 2 Earths, and the radii would be 1.3 Earths, the gravity would be 30% stronger than here.

[Nothalogh]

19 minutes ago, Spaceception said:

1.3 g, The mass would be 2 Earths, and the radii would be 1.3 Earths, the gravity would be 30% stronger than here.

Thanks for the clarification, though the odd of colossal bird crap are still high

[Bill Phil]

1 hour ago, Spaceception said:

1.3 g, The mass would be 2 Earths, and the radii would be 1.3 Earths, the gravity would be 30% stronger than here.

According to my calculations that's actualky 1.18g....

GM/R^2=a

Put in earth's mass times 2 for M, and 1.3 times earth's radius for R.

Actually, 2 divided by 1.3^2 would get a multiple of g... Since all of the other factors arts the same.

[Spaceception]

18 minutes ago, Bill Phil said:

According to my calculations that's actualky 1.18g....

GM/R^2=a

Put in earth's mass times 2 for M, and 1.3 times earth's radius for R.

Actually, 2 divided by 1.3^2 would get a multiple of g... Since all of the other factors arts the same.

Well, it also depends on the composition, like the ratio of Water, Iron, and SIlicates, and the density.

Are your calculations assuming that it has the same composition/density as Earth? I'm just wondering.

Edited February 8, 2016 by Spaceception

[Bill Phil]

6 minutes ago, Spaceception said:

Well, it also depends on the composition, like the ratio of Water, Iron, and SIlicates, and the density.

Are your calculations assuming that it has the same composition/density as Earth? I'm just wondering.

I'm just using your values for mass and radius.

[Spaceception]

6 minutes ago, Bill Phil said:

I'm just using your values for mass and radius.

Oh, well, it can still depend.

[Bill Phil]

2 minutes ago, Spaceception said:

Oh, well, it can still depend.

Not really. Gravity is dependent on mass and distance. The radius and mass you provided don't create a 1.3g environment.