Super-Earths May Be Hostile To Life

[Dragan Glas]

Greetings,

Pause for thought...

Super-Earths may be hostile to life.

Kindest regards,

James

 

[sgrunterundt]

At first I thought "wouldn't they still be molten further out where the pressure is lower?"

But of course "further out" may be so far out that there is not much iron. The earths molten layer is mainly iron. A bigger planets molten layer may be just rock.

 

[Womble]

????

Indeed, I wonder what they're attempting to infer because jupitor has a fricken mahoosive magnetosphere and it's the fat bastard to the Austin Powers of the Earth. Also if you increase the presure you just need a higher temperature for something to still be molten at dept.....and increasing the pressure will also increase the temperature.

If we extrapolate (this is going to be complete guess work) that the geothermal gradient of these super earths are close to ours (which requires similar rock) then for ever 1km down we go the temp goes up 30 degrees celcious, and our planet is just over 6k km to the centre......which is pretty damn hot by the time you get there.....so add on some more KM's and you are REALLY roasting your nuts off.

 

[Cando]

Would the goldilocks zone for a massive planet also have to be massive (ie in proportion to the size of the planet, or the diameter of its orbit, or even the size of its sun)?

 

[SagansHeroes]

Would the goldilocks zone for a massive planet also have to be massive (ie in proportion to the size of the planet, or the diameter of its orbit, or even the size of its sun)?

Goldilocks zone is to do with planets (and a lesser extent their moons) in relation to the star. It's is almost entirely associated with the stars size and type. Where the suns radiation can heat up the surface of the planet/moon between 1 and 99 degree's Celsius I guess. These calculations would attempt to account for greenhouse/anti greenhouse gases. For example Venus is many times hotter than Mercury which is much closer to the star.... Whereas Titan is incredibly cold because it's atmosphere reflects a large amount of sunlight (AND distance of course)

 

[PatrickTheScienceGuy]

interesting, but i though the gravity would cause issues, you know water pressure, boiling point, life, temperature and so on. perhaps someone could correct me.

 

[sgrunterundt]

Indeed, I wonder what they're attempting to infer because jupitor has a fricken mahoosive magnetosphere and it's the fat bastard to the Austin Powers of the Earth.

Jupiter is not a terrestrial planet but a gas giant. Its magnetic field is generated by hydrogen not iron. You cannot compare it like this.

Also if you increase the presure you just need a higher temperature for something to still be molten at dept.....and increasing the pressure will also increase the temperature.

If we extrapolate (this is going to be complete guess work) that the geothermal gradient of these super earths are close to ours (which requires similar rock) then for ever 1km down we go the temp goes up 30 degrees celcious, and our planet is just over 6k km to the centre......which is pretty damn hot by the time you get there.....so add on some more KM's and you are REALLY roasting your nuts off.

That is what theories, models and simulations are for. Taking into account gravitational heat from formation, heat from radioactive decays, convection, heat conduction et cetera. Apparently theirs show that a "big earth" won't have liquid iron.

If you disagree then you will need better arguments than this.