Questions tagged [planets]

Celestial body that orbits following an elliptical path around a star or stellar remnant.

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What would the collision between a (large) solid planet and a gas giant be like?

Assuming a Jupiter-like planet and an Earth-like planet (Except, say... half the mass of Jupiter), what would happen when the two collide? For clarification: What would the actual collision be like? ...
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What's the cause of this gap in this simulation of the Nice model?

A previous question brought me to this video (which has a spectacular change at about 0:34). It shows the orbits of Jupiter, Saturn, Uranus, Neptune, and what appear to be trans-Neptunian objects. ...
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How does Planet 9's perihelion and aphelion affect the Kuiper belt objects?

Assuming that the existence of Planet 9 is confirmed and it really exists, how does it affect the orbits of the Kuiper belt objects? My understanding is that the discovery came in part from the ...
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Protoplanetary disks, angular momentum and prograde orbits

Very similar question at Astronomy SE: https://astronomy.stackexchange.com/q/6183/4042 Given a typical protoplanetary disk made up of the usual planetary system stuff, dust and gas and whatnot, ...
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How did the radiative flux of each gas giant planet change with respect to time (since their formation)?

We know that each gas giant planet was warmest when it was young. This warmth came from internal heating from both radioactive decay and from gravitational potential energy. This warmth, in turn, ...
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Are planets without large moons getting weaker magnetic fields?

Recently I read a study according to which in order for a terrestrial planet to have a magnetic field, a sufficiently large satellite is needed, since the satellite's gravitational influence melts the ...
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Can we rule out life swimming in the oceans of Europa and Enceladus on the basis of a lack of available energy?

Jupiter's moon Europa and Saturn's moon Enceladus (and several other moons too) have large subsurface oceans of liquid water, an ingredient considered essential for life. These two moons occasionally ...
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Barycenter correction for inner planets in solar system?

I want to run simulations of the solar system, and I've read in some papers that to speed up the simulations it is useful to use the barycenter correction of the inner planets (from Mercury to Mars), ...
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How can a gas giant be said to have an atmosphere?

They are made of gas, right? So, there won't be a solid-gas or liquid-gas boundary that defines where the atmosphere starts. So, if there isn't a boundary, we can't define part of it to be an ...
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Had the centrifugal force of the rotation of Earth in the past forced liquid, hot Pangea to be positioned near the Equator?

Had the centrifugal force of the rotation of Earth in the past forced liquid, hot Pangea to be positioned near the Equator? Maybe also a question for 'GSE' but if we deal with centrifugal forces and ...
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Theoretical lower limit to the density of a planet

If a celestial body is too dense, hydrogen fusion will ignite and it will become a star. As such, there is an upper limit on the density a planet can have. But is there a lower bound on the density ...
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Could a planet experiencing tidal locking have a habitable area?

I wonder if it would be possible that, on a planet that always shows the same face towards the sun, there is a habitable area for some life-form similar to that of the Earth. I guess, since one face ...
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1answer
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Uranus: The Spin

In his prog. , on the outer planets, Brian Cox stated that Uranus spins on its side because it once endured an interplanetary collision. Such a cataclysm would normally be devastating for both ...
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Long-term fate of hydrogen atoms in a rogue planet

Imagine a rogue planet drifting in intergalactic space. For the sake of specificity, suppose that it is the size of Jupiter and composed of pure hydrogen. What will happen to it over the next $10^{...
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Jupiter's formation

Two days ago i went to a mathematics conference where there was a paper presented on Jupiter's formation via disk-instability model. I know that there are two different theories for the formation ...
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What happens when a planet's core freezes?

We know the Earth's interior is differentially rotating -- the core is rotating much more quickly than the crust. This is possible because the outer core is liquid and is presumably low enough ...
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How strong can tidal forces get?

I am imagining a planet the size of Earth being in close proximity to something of high mass such as a gas giant or a star, but ultimately I'd be more interested in how to figure this out myself. So (...
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Could there be a planet just as the Earth, but bigger?

Could there be a planet twice or thrice the size of Earth but while being the same? and by the same I mean, hosting the same life as Earth, having a day last 24 hours and a year 365 days. Basically, ...
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Only gravitation and Newton's $2^{\mathrm{nd}}$ law needed to derive Kepler's laws?

It is known that Kepler's laws of planetary motion can be derived from Newton's laws of motion and his law of universal gravitation. However, are all of Newton's laws of motion necessary? According ...
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What speed should have an alone planet to have a habitable zone due to relic radiation?

What speed should have an alone planet to have a habitable zone due to relic radiation, without any star involvement? How much time the planet will be able to remain in the habitable zone before the ...
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Stable planetary rotation states

In reading an article about theories as to how the slow retrograde rotation of Venus may have come into being, the article Why Venus Spins the Wrong Way (Franzen, 2001) stated that it is bound to ...
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For two planets in a 2:1 mean motion resonance , where will their periastron and apastron points be?

I want to animate the changing orbits of planets when they enter a mean motion resonance. Using a 2:1 resonance, I want to show a low-mass inner planet and a low-mass outer planet being tugged by a ...
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How do I find equations for the distance of the planets relative to one another?

I know I should be able to piece together some basic Newtonian equations for this, but I'm not sure where to start. I want to be able to choose one planet as the center and calculate its distance ...
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How can you calculate the atmospheric layers on another planet?

I'm working on a program that procedurally generates planets, and I'd like to make a realistic atmosphere with realistic pressures at different altitudes. I know that for earth we have 7 layers to our ...
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How are the locations of solar system planets expressed in their orbits?

and where can I find the data about the locations of the solar system planets during their entire year? I would like to find the data on the orbits of solar system plantes. Also I would like to know ...
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Find minimum radius of an asteroid before it becomes round using bulk modulus and hydrostatic equilibrium

How big must an asteroid be before gravity makes it round and hydrostatic equilibrium comes into the equation? Let's say that being a round planet requires a radius error of $\frac{\delta R}{R}$ that ...
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2answers
51 views

Is there a smooth transition from inverse quadratic gravity to linear gravity?

I can't remember exactly what it was, but I remember going through a problem in physics related to gravity on and inside a sphere, and found that inside, gravity acts linearly as a result of some ...
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When do planets formed via core accretion in a proto-planetary disk stop gaining mass?

I was just trying to go over some of the contents in my exo planets course and wanted to know that if all the planets that form via core accretion continue to attract all the dust in a proto-planetary ...
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Between Mercury and Venus, which planet produces a longer transit? Assuming both planets describe same path on the solar disk

Is it even possible to give a definite answer to this question? There are a lot of factors involved in this like Earth's position and motion relative to the planets and of course their own motion and ...
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How does the NASA InSight lander determine the depth of a Marsquake?

With only one lander with this type of equipment at one location, how can the InSight lander's investigators be so sure of the depth of the Marsquakes it detects?
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Why is Jupiter's ring system so faint?

Planetary ring systems are formed when asteroids, comets, or any other large objects pass too close to the planet and are torn apart by the planet's gravity [1]. Jupiter is often called the "punching ...
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Does frame-dragging affect planets?

The question has come up many times as to why the planets in our solar system lie in essentially the same plane. The most common answer is that they started out that way due to the accretion disk ...
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On a planet with winds faster than sound, what would it sound like?

I'm watching a Youtube video of the strangest planets and some of them have atmospheres/winds that constantly go at like 20x the speed of sound, ex: HD 189733-b .On earth, fast winds is actually ...
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234 views

Heat transfer on Mars

SCENARIO: I have been tasked with finding the heat transfer across a composite wall on Mars. On the left of the wall there is air maintained at Earth atmospheric conditions and room temperature (101 ...
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How severe would the consequences be if the earth's moon were wrenched from orbit?

The old TV series Space 1999 from the early 1970s seems to have resurfaced on Youtube reminding me of something I watched as a child. It is one of those obviously ridiculous SciFi series (from the ...
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Gravity train and fastest path

As a fun exercise to kill some time, I have been thinking in the gravity train. For a point mass falling through a tunnel dug from pole to pole in an spherically symmetric planet of radius $R$, the ...
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Which planets would be visible from the Saturn system using the Naked Eye?

I was wondering which planets would be visible using the Naked Eye from Saturn? Would these planets always be visible or disappear as they got further from Saturn? Plus which planets wouldn't visible ...
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How is the precession rate of planets calculated? For which planets do we know the precession rates?

From what I've read, precession rates of Earth, Mars and Moon are known. Why is that? And how is it calculated?
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How does the Greenhouse Effect of $CO_2$ modify the classical explanation for atmospheric lapse rate?

Classical physics theory relating to gravity and the properties of gases seems to dictate that the lapse rate of a planetary atmospheres is determined by just 2 factors. The equation being $-g/c$, ...
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Mars' Moons and its Dynamo

Given we could move Mars' moons, Phobos and Deimos, closer to each other, such that the gravitational effect between Mars and its moons is similar to the effect that Earth and its moon have on each ...
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Would a celestial body in a horseshoe orbit be tidally locked to the planet?

A smaller celestial body like a moon or an asteroid can be in a horseshoe orbit around a planet. Since it might go inside the tidal lock radius (but does not stay inside it all the time), during the ...
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Sedna, VP113 and the likelihood of the PX/Tyche/Thelistos hypotheses

The recent discoveries in exoplanetary science (specially those findings of planets orbiting far far away from its parent star/stars) raise questions about how much we know about the (true, AIU ...
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Is the compass direction of a planet recorded by two different observers separated by some distance the same?

I have a basic doubt. Say I am viewing Mars from my window and I used the compass app to get an approximate 2D direction. If at the same instant another person also observes Mars from their window. ...
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Planar Mercury Orbit

Recently we had an exercise about the precession of Mercurys perihelion. It went like this: Using the Schwarzschild-solution of Einsteins field-equations, we can derive the Lagrangian for a test ...
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2answers
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Why does the sun and gas planets in our solar system weigh more than the earth?

I was reading a space.com article about What Is The Sun Made Of? The article says that the sun is made of plasma and gas. If this is the case, how is it that the earth which is solid weighs less than ...
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Liquid metal p-trap entry into an underground base on planet Mercury

Imagine we one day establish a colony under the surface of planet Mercury and use integrated thermal acoustics to stabilize the subterranean environment. With a both heat and cold storage available, ...
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Should larger rocky planets eventually crack due to temperature differences between their inner and outer layers?

Should larger rocky planets eventually crack due to temperature difference between their layers? When a tick piece of glass is left to cool down it would eventually crack...but this is caused ...
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Saturn's moons - getting a stable harmonic model for Mimas and Encyladus

I have built a HTML/Javascript solar system model. It is working well with real time animation. https://abetz-rouse.com.au/planetarium I don't want to get into the deficiencies of my choice of ...
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Is there a gas present in the Martian atmosphere similar to hydrogen?

is there a gas present in the Martian atmosphere which could be extracted to inflate a balloon with sufficient lift to support an instrument platform for low altitude reconnaissance.
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Could the hypothetic water bodies on Mars be 'stable' only if they were large like Earth's oceans?

Could the hypothetic water bodies on Mars be 'stable' only if they were large like Earth's oceans which needs macroscopic basins? Are possible rivers and lakes enough to ,mantain all the water.As ...