The discussion centers on the arrangement of celestial bodies in the Solar System, specifically why planets orbit in a relatively flat plane, known as the ecliptic. Participants explore the implications of gravitational and rotational dynamics on the formation of this planar structure, while also considering the characteristics of other objects like comets and the Oort cloud.
Participants express differing views on the exact nature of planetary orbits and the implications of their inclinations. While there is some agreement on the influence of gravitational and rotational dynamics, the discussion remains unresolved regarding the specifics of orbital inclinations and the characteristics of the Oort cloud.
Participants note that while major planets have orbits close to the ecliptic, there are significant exceptions, such as Pluto. The discussion also highlights the complexity of celestial mechanics and the influence of gravitational interactions on the shapes of various structures in the Solar System.
Borek said:That's not exactly true - while planets orbits do lie close to ecliptic, they are all more or less inclined.
From what I remember initial cloud from which Sun and planets formed get flat as a result of gravitation and rotation.
D H said:This question was asked just a couple of days ago. See [thread=441523]this thread[/thread] and my response in [post=2951827]post #2[/post].
The Opik-Oort cloud is roughly spherical. The members of the Oort cloud have, in many instance, been ejected from the solar system by gravitational interaction with Jupiter or the other giants. Since the ejection can be in any direction they tend to form such a sphere. I think there is some thought that the innermost part of the cloud is also planar, like the rest of the system.AC130Nav said:What shape is the Oort cloud?