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''Habitable'' planet close to a star
Could a habitable planet form with no major bodies of water?Resources for Climate World buildingHow close to each other can Earth-like planets plausibly form from the protoplanetary disk?A spacecraft the size of Apollo 11's lunar module, composed of antimatter, around a normal starHow far could a planet be from its star and still be kept habitable by intense greenhouse gases?Reality Check: Habitable moon around earth-like planetWhat are the atmospheric conditions on a planet tidally locked to its moon?Is a star orbiting around planets(not a single planet) possible?Tidally locked dual planet system and their magnetospheresAn Eden-like moon orbits a barren terrestrial planet. Why is the planet barren while its moon is earthlike?Habitable zone around a Blue SupergiantHow far away from a Sol-class sun could a planet be and still be habitable?Rotation period of a planet around a star (sun)
.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty margin-bottom:0;
$begingroup$
Imagine if you will a star comparable with our sun and a planet like earth orbiting at roughly the same distance around this star as our earth around the sun.
Would it be possible to place a planet somewhere between this ''earth analogue'' and the star/sun at such a distance as to get a planet comprised almost (if not) entirely of deserts and hot as all hell (compared to average earth temperatures,so anything above 48 degrees Celcius is fine) while still having liquid water (just not much of it and if needed not neccesarily above ground) and a breathable atmosphere.
ps. If such a world is possible could it still have plant life? (if need be subterranean in caves or something like that)
planets habitability
$endgroup$
add a comment |
$begingroup$
Imagine if you will a star comparable with our sun and a planet like earth orbiting at roughly the same distance around this star as our earth around the sun.
Would it be possible to place a planet somewhere between this ''earth analogue'' and the star/sun at such a distance as to get a planet comprised almost (if not) entirely of deserts and hot as all hell (compared to average earth temperatures,so anything above 48 degrees Celcius is fine) while still having liquid water (just not much of it and if needed not neccesarily above ground) and a breathable atmosphere.
ps. If such a world is possible could it still have plant life? (if need be subterranean in caves or something like that)
planets habitability
$endgroup$
1
$begingroup$
Not likely as a habitable planet. Related: Could a habitable planet form with no major bodies of water?
$endgroup$
– Alexander
7 hours ago
$begingroup$
Possible useful reading is the series of questions starting here on creating the largest possible percentage of desert for a continent.
$endgroup$
– Ash
7 hours ago
add a comment |
$begingroup$
Imagine if you will a star comparable with our sun and a planet like earth orbiting at roughly the same distance around this star as our earth around the sun.
Would it be possible to place a planet somewhere between this ''earth analogue'' and the star/sun at such a distance as to get a planet comprised almost (if not) entirely of deserts and hot as all hell (compared to average earth temperatures,so anything above 48 degrees Celcius is fine) while still having liquid water (just not much of it and if needed not neccesarily above ground) and a breathable atmosphere.
ps. If such a world is possible could it still have plant life? (if need be subterranean in caves or something like that)
planets habitability
$endgroup$
Imagine if you will a star comparable with our sun and a planet like earth orbiting at roughly the same distance around this star as our earth around the sun.
Would it be possible to place a planet somewhere between this ''earth analogue'' and the star/sun at such a distance as to get a planet comprised almost (if not) entirely of deserts and hot as all hell (compared to average earth temperatures,so anything above 48 degrees Celcius is fine) while still having liquid water (just not much of it and if needed not neccesarily above ground) and a breathable atmosphere.
ps. If such a world is possible could it still have plant life? (if need be subterranean in caves or something like that)
planets habitability
planets habitability
edited 7 hours ago
Blue Devil
asked 8 hours ago
Blue DevilBlue Devil
1487 bronze badges
1487 bronze badges
1
$begingroup$
Not likely as a habitable planet. Related: Could a habitable planet form with no major bodies of water?
$endgroup$
– Alexander
7 hours ago
$begingroup$
Possible useful reading is the series of questions starting here on creating the largest possible percentage of desert for a continent.
$endgroup$
– Ash
7 hours ago
add a comment |
1
$begingroup$
Not likely as a habitable planet. Related: Could a habitable planet form with no major bodies of water?
$endgroup$
– Alexander
7 hours ago
$begingroup$
Possible useful reading is the series of questions starting here on creating the largest possible percentage of desert for a continent.
$endgroup$
– Ash
7 hours ago
1
1
$begingroup$
Not likely as a habitable planet. Related: Could a habitable planet form with no major bodies of water?
$endgroup$
– Alexander
7 hours ago
$begingroup$
Not likely as a habitable planet. Related: Could a habitable planet form with no major bodies of water?
$endgroup$
– Alexander
7 hours ago
$begingroup$
Possible useful reading is the series of questions starting here on creating the largest possible percentage of desert for a continent.
$endgroup$
– Ash
7 hours ago
$begingroup$
Possible useful reading is the series of questions starting here on creating the largest possible percentage of desert for a continent.
$endgroup$
– Ash
7 hours ago
add a comment |
4 Answers
4
active
oldest
votes
$begingroup$
You're basically talking about Venus. Or, more accurately, Venus if it had started out with a lot less water and CO2. Less water and CO2 to start with mean you never get the runaway greenhouse effect Venus has, leaving you a planet that's a lot like Earth, just dryer and hotter. Any rainfall you DID get would be the higher latitudes and that's where you could have plant life, although it'd be evolved for very arid conditions, just like the plants in the American Southwest.
EDIT: If you want this planet to be habitable, you also need it to have a working magnetic field, which Venus does not due to its slow rotation and/or internal composition.
$endgroup$
$begingroup$
This suddenly sounds a lot easier to attain and explain than i though it was gonna be.
$endgroup$
– Blue Devil
7 hours ago
$begingroup$
Just understand that no matter what you're going to have SOME climatic variation just based on latitude, if nothing else. Temperatures will be cooler as you travel towards the poles, you can't avoid that, but as long as you're not trying to postulate a uniform desert planetwide, you're ok.
$endgroup$
– Morris The Cat
7 hours ago
$begingroup$
I was going to suggest putting it a little further out than Venus, say in a 300 day orbit -- but this is the essence of it. +1
$endgroup$
– Zeiss Ikon
7 hours ago
1
$begingroup$
@ZeissIkon You could, but you don't have to. You could get a planet like the OP describes even at Earth's orbital distance if our atmosphere were different enough.
$endgroup$
– Morris The Cat
7 hours ago
$begingroup$
Venus possibly didn't start with any Carbon Dioxide at all, I can't think what the article's called off the top of my head but it suggested that Venus was originally a wet world but due to not having its own magnetosphere the young sun ionised its water releasing hydrogen that blew away on the stellar winds and radical oxygen that stripped carbon and sulfur from the crust forming the modern CO2 and sulfuric acid atmosphere.
$endgroup$
– Ash
7 hours ago
|
show 9 more comments
$begingroup$
Models suggest that a desert planet (that is to say, a planet with some polar surface water, but otherwise dominated by land), can remain habitable as close as ~0.75 AU from a star with luminosity of 1 Sol (Abe et al. 2011).
This is only a touch further out than Venus's orbit, which has a semi-major axis of 0.723 AU. However, it is important to consider that main-sequence stars do grow hotter as they age, so if your planet began life near this inner boundary, it may not remain habitable as the star grows older and the habitable zone expands.
To establish where this boundary lies for other classes of star, apply the equation: $0.75 sqrt L $, where L is the star's luminosity.
$endgroup$
add a comment |
$begingroup$
I believe that in theory an Earth-like world can orbit the Sun at any distance beyond about 0.011AU from Earth's orbital track, thus being outside Earth's Hill Sphere when they're at closest approach. In reality you'd need it to be farther in since orbits are rarely perfectly circular and the smaller the gap between the orbital tracks the less stable the orbits will tend to be. How close you need to get the world for the conditions you want is a balancing act between greenhouse gas concentration in the atmosphere, surface water, ice and stellar output.
Any world closer to the sun than Earth will receive more radiation, in proportion to how close it is to its star, but if it's also relatively dry, having little water that cycles through the atmosphere, then other greenhouse gases will be needed to keep it from freezing over anyway. This presents some issues when it comes to having plant life. The first green "plants" (using the term loosely) to evolve on Earth irrevocably altered our atmosphere going away from CO2 as the main greenhouse gas while increasing water vapour and methane instead. Without large amounts of water vapour to fill the gap Earth-like plants wouldn't be a good idea. However before those first green plants evolved there were other photosynthesisers, on Earth they didn't get very far but they could evolve further in an environment with no competition and you have plants that don't effect the atmospheric greenhouse effect.
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1
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"orbits are rarely perfectly circular" I'd be curious to know even one known orbit with eccentricity = 0. Can you enlighten me? I know there are some that are pretty darn close but still elliptical; those don't count.
$endgroup$
– a CVn♦
3 hours ago
add a comment |
$begingroup$
As was stated already, having less water might allow for your planet to have higher temperatures without triggering a runaway greenhouse effect which would boil away the oceans and cover the world in steam.
And being closer to the sun would make the planet hotter than it would be otherwise.
But there would be more to the climate of a global desert than just having high temperature and low humidity.
Deserts dissipate heat quickly. At night they regularly drop below freezing. Strong temperature differences produce strong pressure differences which in turn produce extreme winds. A global desert without a very dense atmosphere that could transfer heat more efficiently, would have extreme winds between dayside and nightside. Sometimes it would even have global storms.
This would cause much erosion which would produce sand. Now, desert sand has much higher albedo than most of Earth's surface (6-7 times greater that of the ocean) and this is why deserts actually dissipate heat so fast, but the really cool cooling potential of sand on a desert planet is another one: Winds kick up dust and sand which blocks some sunlight temporarily - volcanoes actually do this by ejecting ash and do cool the Earth and it is predicted that meteor impacts would too because they would kick up so much dust. Without rain, dust takes longer to settle down from the atmosphere. So, besides cold nights, there could be cool, dark, dusty days after global storms. Global dust storms are a real thing, at least on Mars - they even hampered the Mars rovers because those were solar-powered. Plants wouldn't be able to get much work done during those days. Just breathing freely could hurt your health because you'd be breathing in all those dust particles.
So, to summarize, not every day could be "hot as all hell", sometimes humans would need air filters (not having them wouldn't kill them quickly, but would hurt their health), and plants would need to be adapted to survive extended periods of low light.
$endgroup$
add a comment |
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4 Answers
4
active
oldest
votes
4 Answers
4
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
You're basically talking about Venus. Or, more accurately, Venus if it had started out with a lot less water and CO2. Less water and CO2 to start with mean you never get the runaway greenhouse effect Venus has, leaving you a planet that's a lot like Earth, just dryer and hotter. Any rainfall you DID get would be the higher latitudes and that's where you could have plant life, although it'd be evolved for very arid conditions, just like the plants in the American Southwest.
EDIT: If you want this planet to be habitable, you also need it to have a working magnetic field, which Venus does not due to its slow rotation and/or internal composition.
$endgroup$
$begingroup$
This suddenly sounds a lot easier to attain and explain than i though it was gonna be.
$endgroup$
– Blue Devil
7 hours ago
$begingroup$
Just understand that no matter what you're going to have SOME climatic variation just based on latitude, if nothing else. Temperatures will be cooler as you travel towards the poles, you can't avoid that, but as long as you're not trying to postulate a uniform desert planetwide, you're ok.
$endgroup$
– Morris The Cat
7 hours ago
$begingroup$
I was going to suggest putting it a little further out than Venus, say in a 300 day orbit -- but this is the essence of it. +1
$endgroup$
– Zeiss Ikon
7 hours ago
1
$begingroup$
@ZeissIkon You could, but you don't have to. You could get a planet like the OP describes even at Earth's orbital distance if our atmosphere were different enough.
$endgroup$
– Morris The Cat
7 hours ago
$begingroup$
Venus possibly didn't start with any Carbon Dioxide at all, I can't think what the article's called off the top of my head but it suggested that Venus was originally a wet world but due to not having its own magnetosphere the young sun ionised its water releasing hydrogen that blew away on the stellar winds and radical oxygen that stripped carbon and sulfur from the crust forming the modern CO2 and sulfuric acid atmosphere.
$endgroup$
– Ash
7 hours ago
|
show 9 more comments
$begingroup$
You're basically talking about Venus. Or, more accurately, Venus if it had started out with a lot less water and CO2. Less water and CO2 to start with mean you never get the runaway greenhouse effect Venus has, leaving you a planet that's a lot like Earth, just dryer and hotter. Any rainfall you DID get would be the higher latitudes and that's where you could have plant life, although it'd be evolved for very arid conditions, just like the plants in the American Southwest.
EDIT: If you want this planet to be habitable, you also need it to have a working magnetic field, which Venus does not due to its slow rotation and/or internal composition.
$endgroup$
$begingroup$
This suddenly sounds a lot easier to attain and explain than i though it was gonna be.
$endgroup$
– Blue Devil
7 hours ago
$begingroup$
Just understand that no matter what you're going to have SOME climatic variation just based on latitude, if nothing else. Temperatures will be cooler as you travel towards the poles, you can't avoid that, but as long as you're not trying to postulate a uniform desert planetwide, you're ok.
$endgroup$
– Morris The Cat
7 hours ago
$begingroup$
I was going to suggest putting it a little further out than Venus, say in a 300 day orbit -- but this is the essence of it. +1
$endgroup$
– Zeiss Ikon
7 hours ago
1
$begingroup$
@ZeissIkon You could, but you don't have to. You could get a planet like the OP describes even at Earth's orbital distance if our atmosphere were different enough.
$endgroup$
– Morris The Cat
7 hours ago
$begingroup$
Venus possibly didn't start with any Carbon Dioxide at all, I can't think what the article's called off the top of my head but it suggested that Venus was originally a wet world but due to not having its own magnetosphere the young sun ionised its water releasing hydrogen that blew away on the stellar winds and radical oxygen that stripped carbon and sulfur from the crust forming the modern CO2 and sulfuric acid atmosphere.
$endgroup$
– Ash
7 hours ago
|
show 9 more comments
$begingroup$
You're basically talking about Venus. Or, more accurately, Venus if it had started out with a lot less water and CO2. Less water and CO2 to start with mean you never get the runaway greenhouse effect Venus has, leaving you a planet that's a lot like Earth, just dryer and hotter. Any rainfall you DID get would be the higher latitudes and that's where you could have plant life, although it'd be evolved for very arid conditions, just like the plants in the American Southwest.
EDIT: If you want this planet to be habitable, you also need it to have a working magnetic field, which Venus does not due to its slow rotation and/or internal composition.
$endgroup$
You're basically talking about Venus. Or, more accurately, Venus if it had started out with a lot less water and CO2. Less water and CO2 to start with mean you never get the runaway greenhouse effect Venus has, leaving you a planet that's a lot like Earth, just dryer and hotter. Any rainfall you DID get would be the higher latitudes and that's where you could have plant life, although it'd be evolved for very arid conditions, just like the plants in the American Southwest.
EDIT: If you want this planet to be habitable, you also need it to have a working magnetic field, which Venus does not due to its slow rotation and/or internal composition.
edited 4 hours ago
answered 8 hours ago
Morris The CatMorris The Cat
6,7071 gold badge17 silver badges35 bronze badges
6,7071 gold badge17 silver badges35 bronze badges
$begingroup$
This suddenly sounds a lot easier to attain and explain than i though it was gonna be.
$endgroup$
– Blue Devil
7 hours ago
$begingroup$
Just understand that no matter what you're going to have SOME climatic variation just based on latitude, if nothing else. Temperatures will be cooler as you travel towards the poles, you can't avoid that, but as long as you're not trying to postulate a uniform desert planetwide, you're ok.
$endgroup$
– Morris The Cat
7 hours ago
$begingroup$
I was going to suggest putting it a little further out than Venus, say in a 300 day orbit -- but this is the essence of it. +1
$endgroup$
– Zeiss Ikon
7 hours ago
1
$begingroup$
@ZeissIkon You could, but you don't have to. You could get a planet like the OP describes even at Earth's orbital distance if our atmosphere were different enough.
$endgroup$
– Morris The Cat
7 hours ago
$begingroup$
Venus possibly didn't start with any Carbon Dioxide at all, I can't think what the article's called off the top of my head but it suggested that Venus was originally a wet world but due to not having its own magnetosphere the young sun ionised its water releasing hydrogen that blew away on the stellar winds and radical oxygen that stripped carbon and sulfur from the crust forming the modern CO2 and sulfuric acid atmosphere.
$endgroup$
– Ash
7 hours ago
|
show 9 more comments
$begingroup$
This suddenly sounds a lot easier to attain and explain than i though it was gonna be.
$endgroup$
– Blue Devil
7 hours ago
$begingroup$
Just understand that no matter what you're going to have SOME climatic variation just based on latitude, if nothing else. Temperatures will be cooler as you travel towards the poles, you can't avoid that, but as long as you're not trying to postulate a uniform desert planetwide, you're ok.
$endgroup$
– Morris The Cat
7 hours ago
$begingroup$
I was going to suggest putting it a little further out than Venus, say in a 300 day orbit -- but this is the essence of it. +1
$endgroup$
– Zeiss Ikon
7 hours ago
1
$begingroup$
@ZeissIkon You could, but you don't have to. You could get a planet like the OP describes even at Earth's orbital distance if our atmosphere were different enough.
$endgroup$
– Morris The Cat
7 hours ago
$begingroup$
Venus possibly didn't start with any Carbon Dioxide at all, I can't think what the article's called off the top of my head but it suggested that Venus was originally a wet world but due to not having its own magnetosphere the young sun ionised its water releasing hydrogen that blew away on the stellar winds and radical oxygen that stripped carbon and sulfur from the crust forming the modern CO2 and sulfuric acid atmosphere.
$endgroup$
– Ash
7 hours ago
$begingroup$
This suddenly sounds a lot easier to attain and explain than i though it was gonna be.
$endgroup$
– Blue Devil
7 hours ago
$begingroup$
This suddenly sounds a lot easier to attain and explain than i though it was gonna be.
$endgroup$
– Blue Devil
7 hours ago
$begingroup$
Just understand that no matter what you're going to have SOME climatic variation just based on latitude, if nothing else. Temperatures will be cooler as you travel towards the poles, you can't avoid that, but as long as you're not trying to postulate a uniform desert planetwide, you're ok.
$endgroup$
– Morris The Cat
7 hours ago
$begingroup$
Just understand that no matter what you're going to have SOME climatic variation just based on latitude, if nothing else. Temperatures will be cooler as you travel towards the poles, you can't avoid that, but as long as you're not trying to postulate a uniform desert planetwide, you're ok.
$endgroup$
– Morris The Cat
7 hours ago
$begingroup$
I was going to suggest putting it a little further out than Venus, say in a 300 day orbit -- but this is the essence of it. +1
$endgroup$
– Zeiss Ikon
7 hours ago
$begingroup$
I was going to suggest putting it a little further out than Venus, say in a 300 day orbit -- but this is the essence of it. +1
$endgroup$
– Zeiss Ikon
7 hours ago
1
1
$begingroup$
@ZeissIkon You could, but you don't have to. You could get a planet like the OP describes even at Earth's orbital distance if our atmosphere were different enough.
$endgroup$
– Morris The Cat
7 hours ago
$begingroup$
@ZeissIkon You could, but you don't have to. You could get a planet like the OP describes even at Earth's orbital distance if our atmosphere were different enough.
$endgroup$
– Morris The Cat
7 hours ago
$begingroup$
Venus possibly didn't start with any Carbon Dioxide at all, I can't think what the article's called off the top of my head but it suggested that Venus was originally a wet world but due to not having its own magnetosphere the young sun ionised its water releasing hydrogen that blew away on the stellar winds and radical oxygen that stripped carbon and sulfur from the crust forming the modern CO2 and sulfuric acid atmosphere.
$endgroup$
– Ash
7 hours ago
$begingroup$
Venus possibly didn't start with any Carbon Dioxide at all, I can't think what the article's called off the top of my head but it suggested that Venus was originally a wet world but due to not having its own magnetosphere the young sun ionised its water releasing hydrogen that blew away on the stellar winds and radical oxygen that stripped carbon and sulfur from the crust forming the modern CO2 and sulfuric acid atmosphere.
$endgroup$
– Ash
7 hours ago
|
show 9 more comments
$begingroup$
Models suggest that a desert planet (that is to say, a planet with some polar surface water, but otherwise dominated by land), can remain habitable as close as ~0.75 AU from a star with luminosity of 1 Sol (Abe et al. 2011).
This is only a touch further out than Venus's orbit, which has a semi-major axis of 0.723 AU. However, it is important to consider that main-sequence stars do grow hotter as they age, so if your planet began life near this inner boundary, it may not remain habitable as the star grows older and the habitable zone expands.
To establish where this boundary lies for other classes of star, apply the equation: $0.75 sqrt L $, where L is the star's luminosity.
$endgroup$
add a comment |
$begingroup$
Models suggest that a desert planet (that is to say, a planet with some polar surface water, but otherwise dominated by land), can remain habitable as close as ~0.75 AU from a star with luminosity of 1 Sol (Abe et al. 2011).
This is only a touch further out than Venus's orbit, which has a semi-major axis of 0.723 AU. However, it is important to consider that main-sequence stars do grow hotter as they age, so if your planet began life near this inner boundary, it may not remain habitable as the star grows older and the habitable zone expands.
To establish where this boundary lies for other classes of star, apply the equation: $0.75 sqrt L $, where L is the star's luminosity.
$endgroup$
add a comment |
$begingroup$
Models suggest that a desert planet (that is to say, a planet with some polar surface water, but otherwise dominated by land), can remain habitable as close as ~0.75 AU from a star with luminosity of 1 Sol (Abe et al. 2011).
This is only a touch further out than Venus's orbit, which has a semi-major axis of 0.723 AU. However, it is important to consider that main-sequence stars do grow hotter as they age, so if your planet began life near this inner boundary, it may not remain habitable as the star grows older and the habitable zone expands.
To establish where this boundary lies for other classes of star, apply the equation: $0.75 sqrt L $, where L is the star's luminosity.
$endgroup$
Models suggest that a desert planet (that is to say, a planet with some polar surface water, but otherwise dominated by land), can remain habitable as close as ~0.75 AU from a star with luminosity of 1 Sol (Abe et al. 2011).
This is only a touch further out than Venus's orbit, which has a semi-major axis of 0.723 AU. However, it is important to consider that main-sequence stars do grow hotter as they age, so if your planet began life near this inner boundary, it may not remain habitable as the star grows older and the habitable zone expands.
To establish where this boundary lies for other classes of star, apply the equation: $0.75 sqrt L $, where L is the star's luminosity.
edited 3 hours ago
answered 4 hours ago
Arkenstein XIIArkenstein XII
3,5899 silver badges35 bronze badges
3,5899 silver badges35 bronze badges
add a comment |
add a comment |
$begingroup$
I believe that in theory an Earth-like world can orbit the Sun at any distance beyond about 0.011AU from Earth's orbital track, thus being outside Earth's Hill Sphere when they're at closest approach. In reality you'd need it to be farther in since orbits are rarely perfectly circular and the smaller the gap between the orbital tracks the less stable the orbits will tend to be. How close you need to get the world for the conditions you want is a balancing act between greenhouse gas concentration in the atmosphere, surface water, ice and stellar output.
Any world closer to the sun than Earth will receive more radiation, in proportion to how close it is to its star, but if it's also relatively dry, having little water that cycles through the atmosphere, then other greenhouse gases will be needed to keep it from freezing over anyway. This presents some issues when it comes to having plant life. The first green "plants" (using the term loosely) to evolve on Earth irrevocably altered our atmosphere going away from CO2 as the main greenhouse gas while increasing water vapour and methane instead. Without large amounts of water vapour to fill the gap Earth-like plants wouldn't be a good idea. However before those first green plants evolved there were other photosynthesisers, on Earth they didn't get very far but they could evolve further in an environment with no competition and you have plants that don't effect the atmospheric greenhouse effect.
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1
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"orbits are rarely perfectly circular" I'd be curious to know even one known orbit with eccentricity = 0. Can you enlighten me? I know there are some that are pretty darn close but still elliptical; those don't count.
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– a CVn♦
3 hours ago
add a comment |
$begingroup$
I believe that in theory an Earth-like world can orbit the Sun at any distance beyond about 0.011AU from Earth's orbital track, thus being outside Earth's Hill Sphere when they're at closest approach. In reality you'd need it to be farther in since orbits are rarely perfectly circular and the smaller the gap between the orbital tracks the less stable the orbits will tend to be. How close you need to get the world for the conditions you want is a balancing act between greenhouse gas concentration in the atmosphere, surface water, ice and stellar output.
Any world closer to the sun than Earth will receive more radiation, in proportion to how close it is to its star, but if it's also relatively dry, having little water that cycles through the atmosphere, then other greenhouse gases will be needed to keep it from freezing over anyway. This presents some issues when it comes to having plant life. The first green "plants" (using the term loosely) to evolve on Earth irrevocably altered our atmosphere going away from CO2 as the main greenhouse gas while increasing water vapour and methane instead. Without large amounts of water vapour to fill the gap Earth-like plants wouldn't be a good idea. However before those first green plants evolved there were other photosynthesisers, on Earth they didn't get very far but they could evolve further in an environment with no competition and you have plants that don't effect the atmospheric greenhouse effect.
$endgroup$
1
$begingroup$
"orbits are rarely perfectly circular" I'd be curious to know even one known orbit with eccentricity = 0. Can you enlighten me? I know there are some that are pretty darn close but still elliptical; those don't count.
$endgroup$
– a CVn♦
3 hours ago
add a comment |
$begingroup$
I believe that in theory an Earth-like world can orbit the Sun at any distance beyond about 0.011AU from Earth's orbital track, thus being outside Earth's Hill Sphere when they're at closest approach. In reality you'd need it to be farther in since orbits are rarely perfectly circular and the smaller the gap between the orbital tracks the less stable the orbits will tend to be. How close you need to get the world for the conditions you want is a balancing act between greenhouse gas concentration in the atmosphere, surface water, ice and stellar output.
Any world closer to the sun than Earth will receive more radiation, in proportion to how close it is to its star, but if it's also relatively dry, having little water that cycles through the atmosphere, then other greenhouse gases will be needed to keep it from freezing over anyway. This presents some issues when it comes to having plant life. The first green "plants" (using the term loosely) to evolve on Earth irrevocably altered our atmosphere going away from CO2 as the main greenhouse gas while increasing water vapour and methane instead. Without large amounts of water vapour to fill the gap Earth-like plants wouldn't be a good idea. However before those first green plants evolved there were other photosynthesisers, on Earth they didn't get very far but they could evolve further in an environment with no competition and you have plants that don't effect the atmospheric greenhouse effect.
$endgroup$
I believe that in theory an Earth-like world can orbit the Sun at any distance beyond about 0.011AU from Earth's orbital track, thus being outside Earth's Hill Sphere when they're at closest approach. In reality you'd need it to be farther in since orbits are rarely perfectly circular and the smaller the gap between the orbital tracks the less stable the orbits will tend to be. How close you need to get the world for the conditions you want is a balancing act between greenhouse gas concentration in the atmosphere, surface water, ice and stellar output.
Any world closer to the sun than Earth will receive more radiation, in proportion to how close it is to its star, but if it's also relatively dry, having little water that cycles through the atmosphere, then other greenhouse gases will be needed to keep it from freezing over anyway. This presents some issues when it comes to having plant life. The first green "plants" (using the term loosely) to evolve on Earth irrevocably altered our atmosphere going away from CO2 as the main greenhouse gas while increasing water vapour and methane instead. Without large amounts of water vapour to fill the gap Earth-like plants wouldn't be a good idea. However before those first green plants evolved there were other photosynthesisers, on Earth they didn't get very far but they could evolve further in an environment with no competition and you have plants that don't effect the atmospheric greenhouse effect.
answered 7 hours ago
AshAsh
31.7k4 gold badges75 silver badges172 bronze badges
31.7k4 gold badges75 silver badges172 bronze badges
1
$begingroup$
"orbits are rarely perfectly circular" I'd be curious to know even one known orbit with eccentricity = 0. Can you enlighten me? I know there are some that are pretty darn close but still elliptical; those don't count.
$endgroup$
– a CVn♦
3 hours ago
add a comment |
1
$begingroup$
"orbits are rarely perfectly circular" I'd be curious to know even one known orbit with eccentricity = 0. Can you enlighten me? I know there are some that are pretty darn close but still elliptical; those don't count.
$endgroup$
– a CVn♦
3 hours ago
1
1
$begingroup$
"orbits are rarely perfectly circular" I'd be curious to know even one known orbit with eccentricity = 0. Can you enlighten me? I know there are some that are pretty darn close but still elliptical; those don't count.
$endgroup$
– a CVn♦
3 hours ago
$begingroup$
"orbits are rarely perfectly circular" I'd be curious to know even one known orbit with eccentricity = 0. Can you enlighten me? I know there are some that are pretty darn close but still elliptical; those don't count.
$endgroup$
– a CVn♦
3 hours ago
add a comment |
$begingroup$
As was stated already, having less water might allow for your planet to have higher temperatures without triggering a runaway greenhouse effect which would boil away the oceans and cover the world in steam.
And being closer to the sun would make the planet hotter than it would be otherwise.
But there would be more to the climate of a global desert than just having high temperature and low humidity.
Deserts dissipate heat quickly. At night they regularly drop below freezing. Strong temperature differences produce strong pressure differences which in turn produce extreme winds. A global desert without a very dense atmosphere that could transfer heat more efficiently, would have extreme winds between dayside and nightside. Sometimes it would even have global storms.
This would cause much erosion which would produce sand. Now, desert sand has much higher albedo than most of Earth's surface (6-7 times greater that of the ocean) and this is why deserts actually dissipate heat so fast, but the really cool cooling potential of sand on a desert planet is another one: Winds kick up dust and sand which blocks some sunlight temporarily - volcanoes actually do this by ejecting ash and do cool the Earth and it is predicted that meteor impacts would too because they would kick up so much dust. Without rain, dust takes longer to settle down from the atmosphere. So, besides cold nights, there could be cool, dark, dusty days after global storms. Global dust storms are a real thing, at least on Mars - they even hampered the Mars rovers because those were solar-powered. Plants wouldn't be able to get much work done during those days. Just breathing freely could hurt your health because you'd be breathing in all those dust particles.
So, to summarize, not every day could be "hot as all hell", sometimes humans would need air filters (not having them wouldn't kill them quickly, but would hurt their health), and plants would need to be adapted to survive extended periods of low light.
$endgroup$
add a comment |
$begingroup$
As was stated already, having less water might allow for your planet to have higher temperatures without triggering a runaway greenhouse effect which would boil away the oceans and cover the world in steam.
And being closer to the sun would make the planet hotter than it would be otherwise.
But there would be more to the climate of a global desert than just having high temperature and low humidity.
Deserts dissipate heat quickly. At night they regularly drop below freezing. Strong temperature differences produce strong pressure differences which in turn produce extreme winds. A global desert without a very dense atmosphere that could transfer heat more efficiently, would have extreme winds between dayside and nightside. Sometimes it would even have global storms.
This would cause much erosion which would produce sand. Now, desert sand has much higher albedo than most of Earth's surface (6-7 times greater that of the ocean) and this is why deserts actually dissipate heat so fast, but the really cool cooling potential of sand on a desert planet is another one: Winds kick up dust and sand which blocks some sunlight temporarily - volcanoes actually do this by ejecting ash and do cool the Earth and it is predicted that meteor impacts would too because they would kick up so much dust. Without rain, dust takes longer to settle down from the atmosphere. So, besides cold nights, there could be cool, dark, dusty days after global storms. Global dust storms are a real thing, at least on Mars - they even hampered the Mars rovers because those were solar-powered. Plants wouldn't be able to get much work done during those days. Just breathing freely could hurt your health because you'd be breathing in all those dust particles.
So, to summarize, not every day could be "hot as all hell", sometimes humans would need air filters (not having them wouldn't kill them quickly, but would hurt their health), and plants would need to be adapted to survive extended periods of low light.
$endgroup$
add a comment |
$begingroup$
As was stated already, having less water might allow for your planet to have higher temperatures without triggering a runaway greenhouse effect which would boil away the oceans and cover the world in steam.
And being closer to the sun would make the planet hotter than it would be otherwise.
But there would be more to the climate of a global desert than just having high temperature and low humidity.
Deserts dissipate heat quickly. At night they regularly drop below freezing. Strong temperature differences produce strong pressure differences which in turn produce extreme winds. A global desert without a very dense atmosphere that could transfer heat more efficiently, would have extreme winds between dayside and nightside. Sometimes it would even have global storms.
This would cause much erosion which would produce sand. Now, desert sand has much higher albedo than most of Earth's surface (6-7 times greater that of the ocean) and this is why deserts actually dissipate heat so fast, but the really cool cooling potential of sand on a desert planet is another one: Winds kick up dust and sand which blocks some sunlight temporarily - volcanoes actually do this by ejecting ash and do cool the Earth and it is predicted that meteor impacts would too because they would kick up so much dust. Without rain, dust takes longer to settle down from the atmosphere. So, besides cold nights, there could be cool, dark, dusty days after global storms. Global dust storms are a real thing, at least on Mars - they even hampered the Mars rovers because those were solar-powered. Plants wouldn't be able to get much work done during those days. Just breathing freely could hurt your health because you'd be breathing in all those dust particles.
So, to summarize, not every day could be "hot as all hell", sometimes humans would need air filters (not having them wouldn't kill them quickly, but would hurt their health), and plants would need to be adapted to survive extended periods of low light.
$endgroup$
As was stated already, having less water might allow for your planet to have higher temperatures without triggering a runaway greenhouse effect which would boil away the oceans and cover the world in steam.
And being closer to the sun would make the planet hotter than it would be otherwise.
But there would be more to the climate of a global desert than just having high temperature and low humidity.
Deserts dissipate heat quickly. At night they regularly drop below freezing. Strong temperature differences produce strong pressure differences which in turn produce extreme winds. A global desert without a very dense atmosphere that could transfer heat more efficiently, would have extreme winds between dayside and nightside. Sometimes it would even have global storms.
This would cause much erosion which would produce sand. Now, desert sand has much higher albedo than most of Earth's surface (6-7 times greater that of the ocean) and this is why deserts actually dissipate heat so fast, but the really cool cooling potential of sand on a desert planet is another one: Winds kick up dust and sand which blocks some sunlight temporarily - volcanoes actually do this by ejecting ash and do cool the Earth and it is predicted that meteor impacts would too because they would kick up so much dust. Without rain, dust takes longer to settle down from the atmosphere. So, besides cold nights, there could be cool, dark, dusty days after global storms. Global dust storms are a real thing, at least on Mars - they even hampered the Mars rovers because those were solar-powered. Plants wouldn't be able to get much work done during those days. Just breathing freely could hurt your health because you'd be breathing in all those dust particles.
So, to summarize, not every day could be "hot as all hell", sometimes humans would need air filters (not having them wouldn't kill them quickly, but would hurt their health), and plants would need to be adapted to survive extended periods of low light.
answered 59 mins ago
aadvaadv
1007 bronze badges
1007 bronze badges
add a comment |
add a comment |
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$begingroup$
Not likely as a habitable planet. Related: Could a habitable planet form with no major bodies of water?
$endgroup$
– Alexander
7 hours ago
$begingroup$
Possible useful reading is the series of questions starting here on creating the largest possible percentage of desert for a continent.
$endgroup$
– Ash
7 hours ago