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The others before me have written plenty about why and how it's not possible normally due to size and density requirements you have set up as a premise. The only way I can think of to make it possible, is make the planet hollow. As long as the outer shell weighs 100x of earth (for 1g, I calculated), the rest should fit into the math more or less. This raises ...


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Orbits are basically falling to Earth and missing. Earth's moon is about 1/4th that of Earth, and while your planet takes up more space than Earth but has the same gravity, it could be possible that an Earth sized moon could occur. The dwarf planet "Charon" is about the same size as Pluto, the body which it orbits, though like manythings about Pluto, it's ...


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The planet is 10 Earth-Radii, with a 1 Earth Gravity value. It is a habitable planet. It has a thin atmosphere. It also has 3 moons and a ring system. Apart from the whole "habitable" and "thin atmosphere" thing, you've basically described Saturn. Saturn is ~95x Earth's mass, and 9.5x Earth's radius at its equator. Surface gravity is a bit over 1g, too. ...


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Your planet would have 0.1 x the density of the Earth, i.e. about half the density of water. It might be some kind of weird smallish gas giant with the right chemistry in its atmosphere to support some kind of life, but definitely not a traditional Earthlike habitable planet. It definitely won't fulfil your description of having a thin atmosphere. Your ...


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Coincidentally I just watched a Scott Manley video on this topic published in May 2018. A small asteroid called 2015 BZ509, and a large gas giant named Jupiter have a resonance in their orbits which is self-correcting. Every time they approach, if the smaller body is too fast or too slow (that is, early or late) the influence of the larger body applies a ...


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Yes it is entirely possible for this situation to occur for a time. However such a situation would probably not be stable long term. Geostationary orbit is well outside of the roche limit for the Earth-Moon system so the Moon should not be disrupted by tidal effects, however the effects on the Earth's tides would be interesting to say the least. Probably ok ...


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NASA recently discovered a very interesting resonant pair in two moons of Neptune, Naiad and Thalassa. Their orbits (nearly <2000km) intersect and have periods of 7 and 7.5hrs respectively. Even though they are quite close at nearest pass (<4000km) they never actually collide because of this ”unprecedented” 69:73 resonance. This resonance was ...


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Planetary nebula rotate around a star during planetary formation and consequently all planets formed orbit in the same direction. So It’s not possible for a planet to be formed with a retrograde orbit in this way. However stars themselves orbit the centre of the galaxy and it is possible that occasionally stars pass in relatively close proximity to one ...


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For an in-situ born planet, it can happen, though it is hard to have the exact chain of events. Basically you need to have a series of gravitational slingshots with a larger body that put your planet on the opposite rotation direction of the entire system. While playing with this simulator, I sometime managed to pull out that stunt, and have a planet ...


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You should have a look at Janus and Epimetheus. They are two moons of Saturn that exchange orbits every once in a while. This setup is probably not stable for more than a few billion years but it might do for what you want. Epimetheus orbits closer to Saturn, so has a shorter orbital period and eventually approached Janus from behind. As they get ...


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Counter-Earth is too massive to stay in any of Earth's L points. As Theraot points out only L4 and L5 are stable for objects much smaller than the main body. Another Earth would be too massive, and also Jupiter is too massive so it would also perturb Earth's L points. So you need to move Jupiter. Move Jupiter to Earth's orbit and then put Earth and ...


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Oh, maybe that is what the magic is about. Under normal circumstances, you can't have perfect synchronous orbits. Suppose the orbits are, to pick numbers, 1000 hours and 10,000 hours. That's about 40 days and about 400 days. So whatever is supposed to happen at the first coincidence might be off by some tiny amount. This tiny discrepancy grows for 400 ...


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Ok, so you say 'Harmonic Orbits', but actual Space-Talking-Dudes call that 'orbital resonance', and it's the solution to your problem. We've got an example of something ALMOST exactly like what you're talking about right here in our own solar system with Pluto and Neptune. As puppetsock rightly points out, their orbits don't actually intersect because of ...


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The elliptical orbit couldn't be terribly long, as all life would cease when it reached the furthest points away from the sun(s) UNLESS there were some sort of greenhouse effect in place. Otherwise, migration wouldn't be too much different than it is on Earth among some tribes and migratory animals. When it's too cold, you go to where it's hot and vice versa....


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Navigation wouldn't be any different than it is on Earth. Consider Pluto: It has a much more eccentric orbit than Earth does, but navigation on Pluto's surface would be exactly the same. The sun rises in the 'East', it sets in the 'West', and North and South are likewise just like they are here. That's all based on the rotation of the planet, orbit has ...


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It's unlikely, on the whole, for a ring system to maintain a high eccentricity on significant timescales. Dissipative collisions tend to circularize the orbits of individual particles, even if the original constituent body traveled on a fairly eccentric orbit. Therefore, you need some external perturbation keeping the particles on substantially elliptical ...


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This is absolutely possible It's all a question of scale. NASA has brainstormed an Asteroid Recovery Mission, a plan to send a small(ish) probe out to an asteroid to tow it out of the asteroid belt and into an intercept course with the Earth-Moon system. A gravitational slingshot around in front of the moon will transfer energy and momentum from the ...


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It is possible for multiple stars to orbit each other Systems containing up to 7 stars are known to exist but are very rare By analogy it would seem likely that 3 planetary sized bodies could orbit each other. However in order to be stable the orbits would need to be specifically arranged such that one pair approximated to a single entity from the ...


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This doesn't work around Sol, at the very least. You calculated that a mega-Jupiter (13 Mj) would have the right angular diameter at ~49M km, which is right around 1/3rd AU. For it to eclipse the sun (which needs to be 1AU away to have the correct angular diameter) then the mega-Jupiter would need to be orbiting the sun with a semi-major axis of only 2/3rd ...


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I note that astronomical bodies are requested with diameters and distances that give them angular diameters of about 0.5 degrees. An object will have an angular diameter of about 0.5 degrees when it is at distance of about 114.59165 times it's diameter. The first thing that Overlord - Reinstate Monica should realize is: The length of seasonal cycles on ...


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I'm pretty sure it can't be done with a gas giant. The problem lies in the stability of the habitable moon's orbit. An object's orbit around its primary is stable as long as it is within the Hill sphere of the primary (the region dominated by the primary's gravity), while being outside the Roche limit (the distance at which tidal forces will break the ...


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TL;DR: maybe. Orbital stability is pretty borderline, and some fairly unlikely circumstances have to arise to produce something that looks like maybe it will fit your needs. Tidal effects and orbital resonances will mess with the figures below, so they're only approximate Lets start with a star the size of the sun, putting the orbit of the planet at 1AU. We ...


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The answer to your question is yes it is possible. The roche limit for 2 equally sized planets is very close. Close enough to allow a shared atmosphere even. Although that is another question and there are other issues, suffice to say that two planets could orbit each other in very close proximity. However such a situation would not be without consequences. ...


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Hmm, it might be possible...but unlikely. To respond to the clarified question (can be found in the comments), let's assume that by "take up the sky" you mean that each planet has almost a 90 degree angular diameter when viewed from the other planet. This will take up 50% of the night's sky. (Getting 100% is impossible due to the curvature of a spherical ...


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