Does it make sense to you that stars are just bunches of gas that are big enough that the self-imposed gravity is enough to create nuclear fusion?
Yes. It makes sense to me that there are objects in space that are, essentially, on fire for a very very long time. But like Jupiter, I have to ask: does a star have a surface?
Yeah, but we have a surface, and IIRC, Venus does, too. How can a planet not have a surface?
Midwinter, I think it is just the language, not science, that has you confused. Point one. You think of a solid surface. What about the ocean? It is liquid and has a surface. The surface is just the top of something, whether it's solid, liquid or a gas. From a perspective in outer space, the atmosphere has a surface and this is what we always see if it is opaque. If it is transparent, we see what is underneath.
Point two. A planet is a concentrated mass revolving about a star, whether that mass is solid, liquid or gas.
Point three. Earth has a core which is molten iron. The surface that you so much seek to have for a planet is simply a crust, in the case of Earth and most other planets. This crust is floating on the molten core.
Jupiter is made of whatever elements were floating around in space in its vicinity, long ago. So its mix may not be quite like earth. Also, the heavier elements sink to the bottom and we cannot see them because of the methane and ammonia. Also, as I mentioned before, it gets hot because of pressure. Being so big the non-gaseous surface may be molten elements that on Earth's surface are solid. Remember, it is almost a star. Iron on Earth is solid. On the sun it is likely gaseous. On Jupiter it may be liquid.
BTW. We don't have methane in our atmosphere because our planet is small enough, and methane escapes. Jupiter is so big that it does not escape. That may be why there is so much of it.
Midwinter, I think it is just the language, not science, that has you confused. Point one. You think of a solid surface. What about the ocean? It is liquid and has a surface. The surface is just the top of something, whether it's solid, liquid or a gas. From a perspective in outer space, the atmosphere has a surface and this is what we always see if it is opaque. If it is transparent, we see what is underneath.
Point two. A planet is a concentrated mass revolving about a star, whether that mass is solid, liquid or gas.
Point three. Earth has a core which is molten iron. The surface that you so much seek to have for a planet is simply a crust, in the case of Earth and most other planets. This crust is floating on the molten core.
Jupiter is made of whatever elements were floating around in space in its vicinity, long ago. So its mix may not be quite like earth. Also, the heavier elements sink to the bottom and we cannot see them because of the methane and ammonia. Also, as I mentioned before, it gets hot because of pressure. Being so big the non-gaseous surface may be molten elements that on Earth's surface are solid. Remember, it is almost a star. Iron on Earth is solid. On the sun it is likely gaseous. On Jupiter it may be liquid.
BTW. We don't have methane in our atmosphere because our planet is small enough, and methane escapes. Jupiter is so big that it does not escape. That may be why there is so much of it.
Q: Is the center of Jupiter really an Earth-sized diamond as claimed by Arthur C. Clarke?
A: We don't really know. It is very hot, possibly as high as 56,000 K, and very dense. The central core pressure is estimated to be 100 million times the atmospheric pressure at the earth's surface.It is expected from a variety of planet formation scenarios that the planet has a rocky core of about 10-15 times the mass of the Earth, but on top of this is a seething 'ocean' of metallic hydrogen and other exotic states of hydrogen and helium, its chief constituents. Whether the central rocky core is in the form of a 'diamond' or not is not something that could be easily anticipated from the mathematical modeling of the planet's interior. In other words, Arthur's guess is as good as anyones!
OK. Simple question: does it have a surface in the sense that Earth does? Something that, if it were possible, you could walk around on?
Id say yes, even if the core is technically liquid, it would be under enough pressure that you would sink through the liquid until its density became high enough to support your weight. Imagine it as a very dense quicksand like surface. You'd only sink so far - walking around might be a problem though.
In effect you would be floating on a 'virtual' surface, where the gravity effecting on your mass would be in equilibrium with the upthrust of the mass below you.
BTW. We don't have methane in our atmosphere because our planet is small enough, and methane escapes. Jupiter is so big that it does not escape. That may be why there is so much of it.
mmm K.
Well, we do have some small amounts of methane here on Earth. Sorry but Methane here is created by 'natural' prosesses. ie Cows and eating beans. Also it is desloved in the Earths magma and there are pockets of it underground. Sorry but. methane is too heavy of a molecule to escape into space. It is broken down in the atmosphere or burned as fuel here on earth. That is why there in not much methane in the atmosphere here.
. . . Sorry but. methane is too heavy of a molecule to escape into space. It is broken down in the atmosphere or burned as fuel here on earth. That is why there in not much methane in the atmosphere here.
Kinetic energy of the methane and ammonia molecules are not all the same, but follow a distribution, so a certain percent do escape, more so than water. The specific gravities are: water -- 18, ammonia -- 17, and methane -- 16.
You did mentioned a reason even more methane and ammonia are lost into space than would be otherwise expected. These two molecules are broken down in the upper atmosphere, due to radiation most likely, and the lighter components escape more easily.
I thought I read somewheres that there were supposedly huge stores of frozen methane (possibly in liquid form) on the ocean floor held there by extremely cold temperatures and pressure... anyone know if that was confirmed?
Quote:
Originally Posted by AquaMac
mmm K.
Well, we do have some small amounts of methane here on Earth. Sorry but Methane here is created by 'natural' processes. ie Cows and eating beans. Also it is desloved in the Earths magma and there are pockets of it underground. Sorry but. methane is too heavy of a molecule to escape into space. It is broken down in the atmosphere or burned as fuel here on earth. That is why there in not much methane in the atmosphere here.
Yes. It makes sense to me that there are objects in space that are, essentially, on fire for a very very long time. But like Jupiter, I have to ask: does a star have a surface?
I don't think there's any matter within a star (or within jupiter) that is classified as a "solid." To be a solid, there is always some crystalline or quasi-crystalline structure at work. At high temperatures and pressures, a solid can't exist.
I thought I read somewheres that there were supposedly huge stores of frozen methane (possibly in liquid form) on the ocean floor held there by extremely cold temperatures and pressure... anyone know if that was confirmed?
Is it? I'm pretty sure at high enough temperature and pressure, everything becomes a condensed plasma. Past that, and things start to get fishy, like in neutron stars and black holes. I'm not sure what these could be classified as.
Is it? I'm pretty sure at high enough temperature and pressure, everything becomes a condensed plasma. Past that, and things start to get fishy, like in neutron stars and black holes. I'm not sure what these could be classified as.
You are talking about temperatures found only in stars.
Comments
Does it make sense to you that stars are just bunches of gas that are big enough that the self-imposed gravity is enough to create nuclear fusion?
Yes. It makes sense to me that there are objects in space that are, essentially, on fire for a very very long time. But like Jupiter, I have to ask: does a star have a surface?
Yeah, but we have a surface, and IIRC, Venus does, too. How can a planet not have a surface?
Midwinter, I think it is just the language, not science, that has you confused. Point one. You think of a solid surface. What about the ocean? It is liquid and has a surface. The surface is just the top of something, whether it's solid, liquid or a gas. From a perspective in outer space, the atmosphere has a surface and this is what we always see if it is opaque. If it is transparent, we see what is underneath.
Point two. A planet is a concentrated mass revolving about a star, whether that mass is solid, liquid or gas.
Point three. Earth has a core which is molten iron. The surface that you so much seek to have for a planet is simply a crust, in the case of Earth and most other planets. This crust is floating on the molten core.
Jupiter is made of whatever elements were floating around in space in its vicinity, long ago. So its mix may not be quite like earth. Also, the heavier elements sink to the bottom and we cannot see them because of the methane and ammonia. Also, as I mentioned before, it gets hot because of pressure. Being so big the non-gaseous surface may be molten elements that on Earth's surface are solid. Remember, it is almost a star. Iron on Earth is solid. On the sun it is likely gaseous. On Jupiter it may be liquid.
BTW. We don't have methane in our atmosphere because our planet is small enough, and methane escapes. Jupiter is so big that it does not escape. That may be why there is so much of it.
Midwinter, I think it is just the language, not science, that has you confused. Point one. You think of a solid surface. What about the ocean? It is liquid and has a surface. The surface is just the top of something, whether it's solid, liquid or a gas. From a perspective in outer space, the atmosphere has a surface and this is what we always see if it is opaque. If it is transparent, we see what is underneath.
Point two. A planet is a concentrated mass revolving about a star, whether that mass is solid, liquid or gas.
Point three. Earth has a core which is molten iron. The surface that you so much seek to have for a planet is simply a crust, in the case of Earth and most other planets. This crust is floating on the molten core.
Jupiter is made of whatever elements were floating around in space in its vicinity, long ago. So its mix may not be quite like earth. Also, the heavier elements sink to the bottom and we cannot see them because of the methane and ammonia. Also, as I mentioned before, it gets hot because of pressure. Being so big the non-gaseous surface may be molten elements that on Earth's surface are solid. Remember, it is almost a star. Iron on Earth is solid. On the sun it is likely gaseous. On Jupiter it may be liquid.
BTW. We don't have methane in our atmosphere because our planet is small enough, and methane escapes. Jupiter is so big that it does not escape. That may be why there is so much of it.
That is VERY helpful! Thank you!
From http://www.astronomycafe.net/qadir/q2270.html:
Q: Is the center of Jupiter really an Earth-sized diamond as claimed by Arthur C. Clarke?
A: We don't really know. It is very hot, possibly as high as 56,000 K, and very dense. The central core pressure is estimated to be 100 million times the atmospheric pressure at the earth's surface.It is expected from a variety of planet formation scenarios that the planet has a rocky core of about 10-15 times the mass of the Earth, but on top of this is a seething 'ocean' of metallic hydrogen and other exotic states of hydrogen and helium, its chief constituents. Whether the central rocky core is in the form of a 'diamond' or not is not something that could be easily anticipated from the mathematical modeling of the planet's interior. In other words, Arthur's guess is as good as anyones!
That is, the boundaries among "really dense, really hot gas" and "really, really hot liquid" and "really, really, really hot solid" are ambiguous?
On account of the enormous pressure?
god this is confusing.
OK. Simple question: does it have a surface in the sense that Earth does? Something that, if it were possible, you could walk around on?
Id say yes, even if the core is technically liquid, it would be under enough pressure that you would sink through the liquid until its density became high enough to support your weight. Imagine it as a very dense quicksand like surface. You'd only sink so far - walking around might be a problem though.
In effect you would be floating on a 'virtual' surface, where the gravity effecting on your mass would be in equilibrium with the upthrust of the mass below you.
If you didn't die first...
hehe - i did put that in, but later editted it out as i didn't want to state the obvious. You might need a Gordon Freeman biosuit...
BTW. We don't have methane in our atmosphere because our planet is small enough, and methane escapes. Jupiter is so big that it does not escape. That may be why there is so much of it.
mmm K.
Well, we do have some small amounts of methane here on Earth. Sorry but Methane here is created by 'natural' prosesses
. . . Sorry but. methane is too heavy of a molecule to escape into space. It is broken down in the atmosphere or burned as fuel here on earth. That is why there in not much methane in the atmosphere here.
Kinetic energy of the methane and ammonia molecules are not all the same, but follow a distribution, so a certain percent do escape, more so than water. The specific gravities are: water -- 18, ammonia -- 17, and methane -- 16.
You did mentioned a reason even more methane and ammonia are lost into space than would be otherwise expected. These two molecules are broken down in the upper atmosphere, due to radiation most likely, and the lighter components escape more easily.
mmm K.
Well, we do have some small amounts of methane here on Earth. Sorry but Methane here is created by 'natural' processes
Yes. It makes sense to me that there are objects in space that are, essentially, on fire for a very very long time. But like Jupiter, I have to ask: does a star have a surface?
I don't think there's any matter within a star (or within jupiter) that is classified as a "solid." To be a solid, there is always some crystalline or quasi-crystalline structure at work. At high temperatures and pressures, a solid can't exist.
I thought I read somewheres that there were supposedly huge stores of frozen methane (possibly in liquid form) on the ocean floor held there by extremely cold temperatures and pressure... anyone know if that was confirmed?
Hydrated methane... yes...
That is patently false spliny...
Is it? I'm pretty sure at high enough temperature and pressure, everything becomes a condensed plasma. Past that, and things start to get fishy, like in neutron stars and black holes. I'm not sure what these could be classified as.
wasn't a new state of existance discovered recently?
I sure thought so, but I just used some Clorox cleanup in the fridge and that took care of it.
Is it? I'm pretty sure at high enough temperature and pressure, everything becomes a condensed plasma. Past that, and things start to get fishy, like in neutron stars and black holes. I'm not sure what these could be classified as.
You are talking about temperatures found only in stars.
You are talking about temperatures found only in stars.
Well, I'm talking about stars. This particular branch of the topic stemmed from comparing Jupiter to a star (the sun).