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Potentially Habitable Exoplanets


Spaceception

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On 31 December, 2015 at 4:12 PM, AngelLestat said:

I would bet that most of those planets (more massive than earth) that are catalogued as in "habitable zone" will be similar to venus in surface temperature.

The atmosphere is the main influence in a planet temperature, not the distance to the star.

Take a look to this table, without greenhouses gases venus would be colder than earth.

ch10image025.gif

Pressure is not a big problem for humans, we can survive without problem pressures from 0.2 bar to 15 bar. We would be able to resist much higher pressures (100 bar) if would not be because the oxygen or nitrogen becomes poison under high pressure, so that gives us a high freedom of choice for atmospheres.

Venus only has a reflectivity of .72 because of the atmosphere. Without atmosphere it would be more like 32° Celsius and an albedo similar to Mars'. It's the clouds. The same thing happens on Earth, to a lesser extent. Actually, removing all the water, life, and air, Earth's albedo would also be similar to Mars'.

Say 0.25 for Mars, Venus, and Earth (not exactly, but it's close enough). A graph using that is below.

World Average Distance from Sun (AU) Vacuum Reflectivity Vacuum Average Surface Temperature Actual Reflectivity Air Pressure (kPa) Actual Average Surface Temperature Atmospheric Warming
Mercury 0.387 11% 164°C 11% Negligible 425°C day, -175°C night -
Venus 0.723 25% 32°C 72% 9300 462°C 430°C
Earth 1 25% -17°C 36% 101.3 15°C 32°C
Mars 1.52 25% -55°C 25% 0.6 -50°C 5°C

Forgot a sixth column here XD, chose to take out Moon since its parameters don't change between this graph and AngelLestat's. 

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I am agree but let's clear something.. is not for the Thick atmosphere.. is for the h2so4 in the clouds that reflect most of the light, and those are measure in 100ppm or less..  We can have an atmosphere like earth with high amount of h2so4 and it will reflect a lot.
One of the global warming solutions is spray the atmosphere with h2so4, you need just a small amount (that will not do any harm we guess) to just stop the global warming.  But we don't know what consequences that might have.. is not advisable to experiment with our atmosphere.

http://www.technologyreview.com/featuredstory/511016/a-cheap-and-easy-plan-to-stop-global-warming/

Edited by AngelLestat
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46 minutes ago, AngelLestat said:

I am agree but let's clear something.. is not for the Thick atmosphere.. is for the h2so4 in the clouds that reflect most of the light, and those are measure in 100ppm or less..  We can have an atmosphere like earth with high amount of h2so4 and it will reflect a lot.
One of the global warming solutions is spray the atmosphere with h2so4, you need just a small amount (that will not do any harm we guess) to just stop the global warming.  But we don't know what consequences that might have.. is not advisable to experiment with our atmosphere.

http://www.technologyreview.com/featuredstory/511016/a-cheap-and-easy-plan-to-stop-global-warming/

It would leave us with the problem of ocean acidification...

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8 minutes ago, Findthepin1 said:

Never heard of the Plato program. Also, the first article said that a planet orbiting a supernova is a primary study thing. How can something orbit a supernova?

Orbiting the supernova remnant in the core (now a neutron star or black hole), but inside a supernova nebula.

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  • 2 months later...
39 minutes ago, Spaceception said:

A new one was found!!!! http://phl.upr.edu/projects/habitable-exoplanets-catalog

                 

019. K2-9 b (N)

Type

M-Warm Superterran

Mass

? - 16.8 - 6.1

Radius

2.2

Flux

1.38

Temp K

276

Period Days

18.4

Distance Ly

359

ESI

0.71

Interesting, my count of habitable exoplanets is 0. Pluto is potentially habitable, provided we have really great compact fusion reactor.

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On 12/16/2015 at 5:03 PM, Spaceception said:

Ohhhhhhhhh, it was a moon, no wonder why it didn't show up on that website, I thought they changed the name or something, my bad. :)

Well, its a hypothetical moon... The say that there is a very large planet there... if the ratio of its moon mass to planet mass is 10,000 :1  (a big assumption, as its basically based on just the gas giants in our system... which would have a lot less moon mass if they were in closer and the moons have a lot of volatiles), *and* all that hypothetical moon mass were concentrated into a single moon rather than a system of moons as we see for all the gas giants (well, Triton dominates Neptunes moons, but its captured, and titan dominates saturns moons, but there's something funny about titan's formation too)... *then* there might be an earthlike moon around this planet

Masses_of_Saturnian_moons.png

Basically, they are hoping for a super titan around a super-jupiter.

There is no evidence at all for this moon, its pure speculation based on the size of the planet and some very shaky assumptions.

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12 hours ago, Scotius said:

Habitable = will not kill you the moment you leave the airlock. :D

As in you suffocate 30 seconds later, not to mention the pounding headache the CO2 gives you, and of course the hydrogen sulfide throws a few punches,

Or are we talking about rapid dehydration due to the lack atmosphere. Or maybe the crushing heat and pressure of mercury venus,

 

Edited by PB666
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6 hours ago, lugge said:

w00t?

fixed it,

10 hours ago, KerikBalm said:

Well, its a hypothetical moon... The say that there is a very large planet there... if the ratio of its moon mass to planet mass is 10,000 :1  (a big assumption, as its basically based on just the gas giants in our system... which would have a lot less moon mass if they were in closer and the moons have a lot of volatiles), *and* all that hypothetical moon mass were concentrated into a single moon rather than a system of moons as we see for all the gas giants (well, Triton dominates Neptunes moons, but its captured, and titan dominates saturns moons, but there's something funny about titan's formation too)... *then* there might be an earthlike moon around this planet

Masses_of_Saturnian_moons.png

Basically, they are hoping for a super titan around a super-jupiter.

There is no evidence at all for this moon, its pure speculation based on the size of the planet and some very shaky assumptions.

You assume that these planets obtain all there mass when they were formed, what if these planets acquire mass from inner solar system and collisions with comets and other orbit crossing objects after they formed, the the planet mass to moon mass would have been initially lower. Are we measuring planet to rocky core? I think we are measuring apples to oranges.

 

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11 hours ago, PB666 said:

You assume that these planets obtain all there mass when they were formed, what if these planets acquire mass from inner solar system and collisions with comets and other orbit crossing objects after they formed, the the planet mass to moon mass would have been initially lower. Are we measuring planet to rocky core? I think we are measuring apples to oranges.

I assume nothing... I was just listing the assumptions they were making for "predicting" the existence of an exo-moon. I'm thoroughly unconvinced that such a moon exists. There is 0 observational evidence that such a moon exists.

They saw a gas giant at a distance from the star that was appealing, and then they used a mass ratio based on a sample size of 4 (our gas giants... which have data skewed by moons like triton and titan), then assumed nearly all the mass was concentrated in one moon (definitely not the case for Jupiter, which would be the planet with the greatest similarity to it in our solar system), then proceeded to "predict" the presence of a "potentially habitable exomoon"

There are sooooo many problems with this prediction... it doesn't belong in a list with places for which there is direct observational evidence.

It is speculation... hypothetically, that planet could have a habitable exomoon... hypothetically... but we can pick pretty much any star in the sky, and without any data, say that hypothetically that star could have a habitable planet around it... that doesn't mean we should start making a list of speculative planets around pretty much every star we can see.

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35 minutes ago, Spaceception said:

Does anyone know the odds of one of these planets being at least somewhat habitable?

This is when it it good to have a sample size greater than 1 :)

Earth is probably not the only configuration that can allow life to survive, so ESI can be misleading.

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Just now, fredinno said:

This is when it it good to have a sample size greater than 1 :)

Earth is probably not the only configuration that can allow life to survive, so ESI can be misleading.

Well then theoretically, with the sample size we have, and ignoring ESI, which planet is the most likely to have at least temperatures comfortable for a human?

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5 minutes ago, Spaceception said:

Well then theoretically, with the sample size we have, and ignoring ESI, which planet is the most likely to have at least temperatures comfortable for a human?

I would anticipate that number to be ESI.

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