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Rifat amin
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can two planets share the same orbit
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DrClaude said:Not by the current definition of a planet
Vanadium 50 said:Here is the definition: A celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.
Exoplanets are not planets.
It does seem reasonable to me that the definition could be applied for any solar system.vela said:According to the IAU site, that's the "definition of a planet in the Solar System." It makes no claims about objects outside our solar system.
https://www.iau.org/static/resolutions/Resolution_GA26-5-6.pdf
I'm going to go out on a limb and say the OP is probably not after a semantic answer and this [great] technical answer will satisfy him/er.Janus said:For a gas giant like Jupiter, some 333 times more massive than the Earth, I don't foresee a problem with maintaining a body of planetary mass ( satisfying parts (a) and (b) of the definition. at its L4 or L5 point.
Whether such body could be technically called a "planet" by IAU nomenclature is another question. I assume it would depend on whether or not having a single mass of that size there would disrupt the collection of other bodies or gather them into orbit around itself.
Rifat amin said:can two planets share the same orbit
Does the classification affect the Physics involved?Vanadium 50 said:Here is the definition: A celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.
Exoplanets are not planets.
It's not as simple as the two satellites following the same path for ever though, is it? They interact, That sort of mutual gravitational effect also means that geostationary satellites need to be spaced a significant distance apart to minimise the amount of fuel needed to cancel their mutual effect and keep them stationary in the same orbital spot.nikkkom said:Sure they can.
Saturn has two moons in coorbital arrangement. Same is possible for planets.
https://en.wikipedia.org/wiki/Co-orbital_configuration
sophiecentaur said:It's not as simple as the two satellites following the same path for ever though, is it?
And they have to be at Lagrange points for this? That has now made things clearer for me.nikkkom said:Basically they do. The periodic change in their orbits' radius is less than the diameters of the satellites.
sophiecentaur said:And they have to be at Lagrange points for this? That has now made things clearer for me.
nikkkom said:In this case, no. They are in mutual "horseshoe" orbits. One is in a lower orbit and thus is faster, it very slowly approaches another, they they exchange momentum (since they attract), and now the leading object is in a lower orbit and thus moves faster, and thus runs away. Counterintuitive.
sophiecentaur said:I have read about horseshoe orbits but to they really pass that close to each other? The diagrams don't seem to suggest that.
The inverse square law operates at all distances and, given the same mutual situation and being put out in deep space, they would have a highly elliptical but 'regular' orbit, wouldn't they? If it were not for the mutual attraction, over the whole period, they wouldn't have the horseshoe orbit.nikkkom said:They come close enough to start feeling a weak mutual attraction.
sophiecentaur said:If it were not for the mutual attraction, over the whole period, they wouldn't have the horseshoe orbit.
Oh yes. Definitely but 'enough' and I would say that it always matters - even when it's hard to measure. AS I commented; if it were not there, there would be no horseshoe.nikkkom said:, their attraction is _very_ tiny.
nikkkom said:Sure they can.
Saturn has two moons in coorbital arrangement. Same is possible for planets.
https://en.wikipedia.org/wiki/Co-orbital_configuration
snorkack said:By definition, no.
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There is no physical reason why Saturn could not orbit in 1:1 resonance with Jupiter. However, in that case, Saturn would be an asteroid - and Jupiter would also qualify as asteroid
No, it is not possible for two planets to share the same orbit without catastrophic consequences. This is because the gravitational pull of each planet affects the other, causing their orbits to become unstable and eventually collide.
Even if the two planets have similar masses, they will still experience gravitational pull from each other which can disrupt their orbits. Additionally, the presence of other celestial objects such as moons or asteroids can also affect the stability of the shared orbit.
No, there are no known examples of two planets sharing the same orbit in our solar system or in other observed planetary systems. This is because the laws of physics and gravity make it highly unlikely for such a scenario to occur naturally.
In theory, it is possible for artificial intervention to make two planets share the same orbit. However, it would require precise calculations and constant adjustments to maintain the stability of the shared orbit. It is not a feasible or practical option for planetary systems.
In a binary system, two planets can orbit around a common center of mass and appear to share the same orbit. However, they are not truly sharing the same orbit as each planet is still affected by the gravitational pull of the other. These systems are carefully balanced to prevent catastrophic consequences and are relatively rare in the universe.