Questions tagged [gas-giants]

Questions regarding massive planets composed of layers of gases, such as hydrogen and helium, surrounding a solid/liquid core.

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5
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1answer
108 views

Is the transition between ice giants and Jupiter-like gas giants somewhat fluid?

The ice giants Uranus and Neptune are often being distinguished from Saturn and Jupiter who consist mostly of hydrogen and helium, while the ice giants have more of heavier elements than hydrogen and ...
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104 views

Spin-down of gas-giants during formation

In the paper https://arxiv.org/abs/1712.00457 about rotation rates of gas giants it says: "owing to accumulation of angular momentum stored in the source material, a planetary mass object should ...
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Gravity of a gaseous planet without a core

Both Jupiter and Saturn have rocky cores. Is there such of a thing as a gaseous planet without a core? And would a planet without a core have gravity?
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44 views

What is the meaning of grain opacity and why does it affect the formation time of gas giants?

While doing research for my presentation on the formation of gas giants, more specifically the "core-accretion model", I have been stumbling across the term "grain opacity" and don'...
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Could there be liquid water on Uranus? Are there any indications that there might be?

Like most planets, Uranus has a very cold outer atmosphere and a very hot core. What we see is a very thick primary atmosphere with plenty of hydrogen. Deeper in, we might suppose that water ...
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1answer
88 views

Is there a link between the amount of swirling and vorticity in a gas giant's atmosphere and its distance to its Sun?

This is an empirical observation of mine: I have noticed that out of the 4 gas giants in our Solar System, Jupiter's atmosphere has the most visible swirls and complex cloud patterns, followed by ...
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1answer
125 views

Maximum and minimum masses and sizes of giant planets?

What are the minimum & maximum masses and diameters of giant planets? Minimum end of the scale Earth has mass of 1 Earth mass and a mean radius of 6,371.0 kilometers, and thus a mean diameter of ...
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68 views

Assuming a hypothetical system without gas but only solid rocks, how big of a planet can form through the coalescing of these rocks?

I have heard that gas giants are primarily huge solid bodies like regular rocky planets that exponentially gained more and more gas in their atmosphere through their increase in mass which they use ...
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54 views

Moons within a Gas Giant

Assuming a gas giant is primarily gaseous past our visibility, is it possible that a moon traveling at a sufficient velocity would be able to exist within the atmosphere, or would terminal velocity ...
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151 views

Why don't we detect planets around OB stars and no terrestrial planets around A or early F stars?

Looking at an exoplanet database, I noticed that there are very few planets detected around main-sequence OBA stars, and most of them are gas giants/brown dwarfs. Why can't we detect low-mass planets ...
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What is the birth of a star like? [closed]

Here's what I'm curious about. So this hydrogen gas collects and at some point, it eventually becomes a star. What does that process look like? If you were there as a witness to the formation of a ...
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Can air/gas be slowed down by friction [closed]

Can wind/air that is moving at average speeds be slowed down by the cause of Friction? Also, Can Air bubbles in water be slowed down because of Friction? Please cite your sources.
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If the fifth gas giant in the early Solar System was completely ejected, where would it be now?

I've read about the possible 5th gas giant in the Solar System, and about its ejection about ~100 million years after the formation of the Solar System. However, I have not seen anything about its ...
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83 views

Could a star become a planet?

Could a star become a planet? I am asking this because the gas giants are ¨Failed Stars¨ and they are classified as planets in our solar system.
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3answers
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Why can't stars be multicolored like gas giants?

Gas giants like Jupiter and Saturn have bands of different colors in their atmosphere. These are due to the rotation of the planets. Stars rotate too, so why do most stars have patches/blotches of ...
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1answer
324 views

Why do the solar system planets go rock-gas-ice instead of rock-ice-gas when moving away from the sun?

The sun and the solar wind seem to do a good job of fractionating lighter materials to the outer solar system and leaving heavier materials in the inner solar system. So we end up with rocky/metallic ...
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1answer
185 views

Life cycle of a gas planet?

I am interested in learning more about the (simplified) life cycle of gas planets which are not brown dwarfs (meaning less than 13 Jupiter masses). It obviously starts off with their creation within a ...
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63 views

Why are gas giants (Jovian planets) spherical in shape? [duplicate]

If the core of the gas giant was square for instance, would the planet be square too?
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121 views

How to calculate the frequency of a gas giant eclipsing the sun from a moon?

Say you have a moon around a gas giant which goes around a star. If the moon has an inclination of around 0° relative to the gas giant's orbit, the gas giant will eclipse the star every orbit of the ...
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Updrafts on Gas Giants

Gas giants put out a fair amount of heat from gravitational collapse, so there's bound to be quite a bit of upward moving winds. If Carl Sagan's idea about aerial ecologies pans out, could larger ...
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22 views

Qualities of gas giant atmospheres at a density of 1 gram per cubic centimeter

At what depth in the atmospheres of the gas giants does the density of their atmospheres equal 1 gram per cubic centimeter? What is the pressure and temperature at these depths? Are the radiations ...
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What is the difference between aurorae and electroglow?

One of the discoveries of Voyager 2 at Uranus was a phenomenon called "electroglow", which as I understand it is related to charged particles interacting with the atmosphere that cause the ...
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What's the critical mass of a rocky planet before its gravity traps enough gas in its atmosphere to start becoming a gassy planet

Looking at the latest theories, I've noticed that most rocky planets are below a certain mass range. I speculate that maybe the way gas giants and gas dwarfs form is a rocky planet during the ...
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Where do we define the "surface" of a gas planet?

Since gas giant consist of most gas components, where do we establish their "surface"? My take is basically to take the limit in which all light is opaque. For example, in this photo: The ...
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Are there other planetary systems where gas giants are on the inside to rocky planet orbits?

I understand that formation theories for gas giants suggest they should be born further away where there is more gas for them to monopolize vs the sun, and then to form Hot Jupiters they need to ...
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Why do gas giants have clearly delineated surfaces, whereas the Earth's atmosphere fades into space?

I've just seen this Forbes article. Why do gas giants appear to have clearly delineated surfaces, whereas the Earth's atmosphere fades into space? Is it just a matter of scale? Or is there some ...
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Satellite grids around other planets [closed]

We send a lot of rovers to Mars, as interesting as the planet could possibly be. But why are we not putting satellite grids around planets that could transmit superficial probe data at the very least?...
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1answer
180 views

What is the gaseous-to-rocky ratio of exoplanets?

Around the Sun, there are as many gaseous planets (Jupiter, Saturn, Uranus and Neptune) as there are rocky planets (Mercury, Venus, Earth and Mars). Do other stars have similar gaseous-to-rocky ...
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1answer
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Is there a clear-cut difference between rocky and gaseous planets?

A gas giant planet is large enough that it retains a lot of hydrogen and helium. A rocky planet is one with a solid surface. That's the rule of thumb to distinguish between the rocky and gaseous ...
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1answer
173 views

Would it be possible for life found on moon of rogue planet

I have heard that there are at least three Basic requirement for life exist in the universe, they are: Source of Energy Complex chemistry (including solvent/medium for chemical reaction) Protection ...
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2answers
205 views

Can a dying, swelling, star be rejuvinated by enveloping orbiting gas giants?

Many hot jupiter type exoplanets have been found, orbiting near their parent stars. At the end of a stars life, they swell up and sometimes envelop closely orbiting bodies. Combine these effects and ...
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577 views

Characteristics of the first planets in the Universe?

What would have the very first planets looked like, based on their most likely chemical compositions? For example: Were they mostly grey gas giants with atmospheres of hydrogen and helium, ...
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58 views

Is there any possibility that a gas planet turns into a star [duplicate]

Since the sun is made of one of elements hydrogen Why Saturn and jupiter doesnt turn into a star since they have a elements of hydrogen ?
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275 views

Are gas giants actually rare?

Kepler data suggests that the vast majority of planets are smaller than 4 Earth radii, with larger planets quickly becoming vanishingly scarce. Yet somehow, our own solar system harbours not just one, ...
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What would happen to the atmosphere of a rogue jovian planet?

Let's say we have a gas giant composed primarily of hydrogen and hydrogen-rich molecules that is ejected from its star system. As this planet embarks on its potentially infinite journey out into the ...
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2answers
99 views

Is there a term for asteroseismology as applied to giant planets?

Giant planets such as Jupiter have oscillations which enable analyses using the techniques of asteroseismology, for example Gaulme et al. (2011) detected global modes on Jupiter via radial velocity ...
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197 views

Birth of the Gas Giant Planets?

How does a gas giant planet form like Saturn and Jupiter, and why just gas? Why didn't they form any solid surface?
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130 views

Can we get the gas compositions from a gas planets? [closed]

Is it possible to get some gases like hydrogen from gas planets (Saturn, Jupiter, Uranus or Neptune)?
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5k views

Why does the Sun have different day lengths, but not the gas giants?

The Sun's rotation period varies from about 25 days at the equator to about 38 days at the poles. As I understand it, this is because the Sun is not solid, and because of the way centripetal force ...
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1answer
157 views

Aren't there any rock or similar firm material on/in the gas giant planets?

Aren't there any rock or similar firm material on/in the gas giant planets? What happens if a rock asteroid hits one of these planets? Shouldn't the rock accumulate in the center of the planet due to ...
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1answer
130 views

Gas Giant temperatures

Sudarsky's gas giant classification predicts the visual appearance of gas giant planets based on their temperatures. But what determines their temperatures in the first place? Is it just the ...
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1answer
81 views

Largest non-hot gas giants

Excluding 'fluffy' or 'puffy' gas giants that are 'inflated by heat from their stars, what is the maximum radius of a gas giant planet. I keep reading things like "...Jupiter is 'about' as big as ...
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1answer
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Warm jupiter vs hot jupiter, fluffyness

If Jupiter was orbiting at 1AU, replacing Earth, but everything else in the solar system remained as it is currently, how much would the increased heat from the sun increase Jupiter's radius? In ...
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1answer
151 views

Terminology question: gas giant vs gas planet

While not exactly the most exciting question, I'm wondering: is there any real, semantic difference between a gas planet and gas giant, or are the two terms used interchangeably by most in popular ...
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2answers
145 views

What percentage of gas giant exoplanets are in the habitable zone?

Approximately what percent of exoplanet gas giants discovered so far are in the habitable zones of their stars? I hear that most of them are "Hot Jupiters", orbiting so close to their stars that the ...
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3answers
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Why does each and every planet of our solar system have an unique axial tilt angle?

Why do planets have an axial tilt? From the above image we can see that each planet's axial tilt angle varies and differs from the others. What was the cause of this, was this from the beginning of ...
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1answer
126 views

Where do gas giants end up?

I want to create a semi realistic star system generator but I am not sure where to "put in" gas giants. My guess is they can form pretty much anywhere within the sphere of influence of a star at the ...
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3answers
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Fate of Jupiter when our sun dies

Five billion years from now, the sun will have grown into a red giant star, more than a hundred times larger than its current size. While this metamorphosis into the giant star will change the solar ...
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1answer
130 views

Floating Masses in Gas Giants

This may be a very stupid question, as I know little about astrophysics, but if solids like Aerogel can float in gasses like sodium hexafluoride, could there be pressures high enough on gas giants to ...
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horseshoe orbits

I'm designing a moon system for a fictional setting, and recently came across the idea of horseshoe orbits. The gist of my question is how many objects can share a horseshoe orbital at a time? I ...