Star's habitable zone?

[Moontanman]

Does the term habitable zone in relation to the brightness of a star and the distance of a planet from a star give rise to misconceptions about exoplanets? Our own solar system is an example, Venus, Earth and Mars are in the habitable zone. A super earth could be habitable well out into the what we call the asteroid belt but would not be if it was close as the Earth. Sara Seager  has suggested that a super earth might be habitable well past the orbit of Jupiter if it had a thick hydrogen atmosphere. 

Then you get into the whole ice planets or moons with frozen over oceans and if we find life on Titan as Chris McKay and Heather Smith have suggested then the entire concept goes out the window? 

[mathematic]

Habitable planet zone means it is possible, not certain that a planet could support life.

[Moontanman]

5 minutes ago, mathematic said:

Habitable planet zone means it is possible, not certain that a planet could support life.

Yes that the point of this. We say habitable zone as though it would apply to every star and planet while the size and atmosphere of the planet dictate the habitable zone as much or more than the star... 

Edited June 9, 2019 by Moontanman

[beecee]

39 minutes ago, mathematic said:

Habitable planet zone means it is possible, not certain that a planet could support life.

More accurately, I think the definition of a "habitable zone" or Goldilocks zone, is a planetary orbit, that can support liquid water?

[Moontanman]

Just now, beecee said:

More accurately, I think the definition of a "habitable zone" or Goldilocks zone, is a planetary orbit, that can support liquid water?

This would be true but it assumes a lot and even our own "goldilocks zone" only applies to the earth since both Mars and Venus lie within the zone. Especially Mars but a super earth with a deep dense atmosphere could expand that zone quite a bit and a smaller planet with a less dense atmosphere could could support life at least to the orbit of Venus. 

[beecee]

2 minutes ago, Moontanman said:

This would be true but it assumes a lot and even our own "goldilocks zone" only applies to the earth since both Mars and Venus lie within the zone. Especially Mars but a super earth with a deep dense atmosphere could expand that zone quite a bit and a smaller planet with a less dense atmosphere could could support life at least to the orbit of Venus. 

Certainly, and also the makeup of the star around which they orbit, and of course the age of the star. 

I always like encasing the definition with "Life as we know it"Jim. 

[Moontanman]

6 minutes ago, beecee said:

Certainly, and also the makeup of the star around which they orbit, and of course the age of the star. 

I always like encasing the definition with "Life as we know it"Jim. 

"he's dead Jim... get his wallet... " 

[Moontanman]

Besides the concept of large rocky planets with atmospheres dominated by hydrogen and water oceans there is the possibility of large ice planets with dense hydrogen atmospheres and oceans of methane. Imagine an ice world 20,000 miles in diameter due to being mostly ice it could have a gravity of one gee due to the cold it could hang on to hydrogen.  They may be more plentiful than earth like worlds.  

[Sensei]

On 6/9/2019 at 12:39 AM, Moontanman said:

thick hydrogen atmosphere. 

Thick atmosphere = large pressure of atmosphere at the surface..

Habitable for human being is the not same as habitable to any organic life form and even less for inorganic forms.. Supply of energy might be due to planet's internal activity e.g. volcanoes, tidal forces etc.

[Moontanman]

51 minutes ago, Sensei said:

Thick atmosphere = large pressure of atmosphere at the surface..

Habitable for human being is the not same as habitable to any organic life form and even less for inorganic forms.. Supply of energy might be due to planet's internal activity e.g. volcanoes, tidal forces etc.

I understand that, I am not thinking of humans, but life in general.