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Prime Evil · 10-25-2009, 03:12 AM

A couple of quick questions for the astronomers out there that don't seem to be covered by GURPS Space...

If a planet has natural satellites, what would be the best way to determine the inclination of the orbits of the various moons with respect to the ecliptic plane?

Is the rotational axis of a moon related to the axial tilt of the planet that it orbits or should you randomly determine the axial tilt of the moon with respect to its own orbital plane?

The table on p.118 of GURPS Space makes it possible to randomly determine the axial tilt of planets. However, the Wikipedia article on axial tilt seems to suggest that the presence of one or more large moons orbiting a planet may provide a stabilizing influence that prevents large variations in axial tilt over time. Is this true? Or am I mis-reading the article? Does this make it less likely that planets with large moons will have a high axial tilt?

10-25-2009, 03:12 AM	#1
Prime Evil Join Date: Mar 2007 Location: Sydney, Australia	[Space] Orbital Mechanics of Moons A couple of quick questions for the astronomers out there that don't seem to be covered by GURPS Space... If a planet has natural satellites, what would be the best way to determine the inclination of the orbits of the various moons with respect to the ecliptic plane? Is the rotational axis of a moon related to the axial tilt of the planet that it orbits or should you randomly determine the axial tilt of the moon with respect to its own orbital plane? The table on p.118 of GURPS Space makes it possible to randomly determine the axial tilt of planets. However, the Wikipedia article on axial tilt seems to suggest that the presence of one or more large moons orbiting a planet may provide a stabilizing influence that prevents large variations in axial tilt over time. Is this true? Or am I mis-reading the article? Does this make it less likely that planets with large moons will have a high axial tilt?