4 ms·
I just wonder so, if there are multiple planets in equal distance between them, would we be able to tell the difference between three planets and one on a fast
by hef19898 3y ago
I just wonder so, if there are multiple planets in equal distance between them, would we be able to tell the difference between three planets and one on a fast orbit?
- TeMPOraL 3y agoThat sounds like aliasing issue in signals; we should be able to distinguish between them as long as we sample more often than half the actual orbital period (i.e. with a sampling frequency larger than the Nyquist frequency). https://en.wikipedia.org/wiki/Nyquist_frequency https://en.wikipedia.org/wiki/Nyquist_frequency
- hef19898 3y agoAnother question, is there something like a max. rotation speed for a planet in a certain distance to a sun of a certain size? Edit as a general response: Question answered, multiple times, thank you! Also, there my basic physics knowledge resurfaces, thank you for that as well!
- TeMPOraL 3y agoYes, but that would be dictated by how fast can it spin before shattering into pieces. So mostly gravity/composition thing, I'd imagine. Many things in solar systems are (postulated to) derive from the rotation of the protoplanetary disk, via conservation of angular momentum - however, planets can also get spun up or down after forming by e.g. collisions with other objects, including extra-system objects.
- hef19898 3y agoJust realized, I meant orbit speed and not rotation aeound the planets axis. Shouldn't write in parallel to meetings... Your answer was very interesting so, thank you!
- TeMPOraL 3y agoI see! In the other case, the answer is: velocity vector determines the orbit. For any given point at any given orbit, there's only one valid velocity vector relative to the star (direction and magnitude) - tweaking it tweaks the shape of the orbit. One of the best way to get an intuition for orbits is to play Kerbal Space Program for a few hours :).
- hef19898 3y agoGoing back to my buried physics knowledge, that is quite logic. Thanks again! I am just afraid to touch Kerbal Space Program, I really cannot afford another time sink at the moment! As one time ovner of a Star Wars RPG PC whos secret super weapon was his tremendous Astrogation skill, I really should so I guess!
- thfuran 3y agoFor a given stellar mass and orbital radius (assuming a circular orbit), there's not really any wiggle room on how long the planet's orbital period is. Speeding up or slowing down the planet requires it to orbit at a different distance. If you meant the speed of a planet's rotation about its own axis, I guess the limit would basically be the point at which it tears itself apart by spinning so fast that its gravity no longer holds it together.
- pavel_lishin 3y agoThere is only one stable speed at which a planet can orbit in a circle; any slower, and it'll start falling in toward the star, and any faster and it'll start to move away from the star. The only way to vary the speed is a powered orbit, and that's not likely to happen with a planet.
- qup 3y agoI respect that you reserved some room to be surprised.