Timeline for Are there any known planets whose axis is oriented such that one pole always faces its star?
Current License: CC BY-SA 3.0
11 events
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| Sep 20, 2016 at 14:57 | vote | accept | LeHill | ||
| Sep 19, 2016 at 22:36 | comment | added | Brock Adams | @called2voyage, Tidal forces cannot align an axis of rotation this way. The reason is gyroscopic force (a force perpendicular to the axis of rotation results in a corresponding force 90 degrees from that). So, any force that tried to keep a rotating pole aligned to the star, would gyroscopically force the pole towards a perpendicular from the orbital plane. Thus, given enough time, all rotating orbital bodies would get their poles aligned in a perpendicular manner. | |
| Sep 19, 2016 at 20:34 | comment | added | Steve Jessop | The answer to that question is that it doesn't matter how the system originally came to be. Compare the angular momentum of the planet's rotation at one point in its orbit, with the opposite point in the orbit. It has the same magnitude but opposite direction, since the axis of rotation of the planet has changed 180 degrees over the course of the half year. The force required to achieve this is what aventurin is saying simply doesn't exist in orbital dynamics. | |
| Sep 19, 2016 at 20:21 | comment | added | called2voyage♦ | From astronomy.stackexchange.com/users/14289/user6694745 | |
| Sep 19, 2016 at 20:20 | comment | added | called2voyage♦ | Part of that angular momentum is retained in the orbit and part in the rotation of planet. This, logicalyy cannot deviate to much form the plane of rotation of original material. But... this should be in a comment: How about if a star traps a wondering plant. This one should have any axis of rotation it likes. Am I wrong about that. Will some kiind of force, like tidal forces, align the roration of the planet?" | |
| Sep 19, 2016 at 20:20 | comment | added | called2voyage♦ | From driveby editor: "I cannot write a comment so I try this way and I hoep original poster wouldn't mind. I in part can understand your reasoning and explain ti to my self like this: The material a planet was made of was circling around the star. | |
| Sep 19, 2016 at 20:19 | review | Suggested edits | |||
| Sep 19, 2016 at 20:21 | |||||
| Sep 19, 2016 at 20:19 | review | Suggested edits | |||
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| Sep 19, 2016 at 20:14 | comment | added | Steve Jessop | "with reasonable inner structure" -- the implication of course is that with unreasonable inner structure, such as a counter-rotating core and some sort of super-science to use one to drive the other in synch with the year, you could rig something up. | |
| Sep 19, 2016 at 19:56 | history | edited | aventurin | CC BY-SA 3.0 |
added 1 character in body
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| Sep 19, 2016 at 19:47 | history | answered | aventurin | CC BY-SA 3.0 |