# Tag Info

-1

Set up a strong temporary field and then hit the planet a couple of times with a big rock to magnetize the core.

2

I am certain that mathematical analysis of tidal locking has been done many times but I have failed to find such an analysis where the mechanism for the transfer of angular momentum to spin angular momentum is included which is the question which has been asked. Perhaps someone is able to produce a reference or an analysis? Having experienced on a number ...

3

What you are asking for is not simple at all. Retrograde motion occurs when the line joining two planets rotates with respect to a fixed coordinate system (or the fixed stars) in the opposite direction as the planets. With both planets in motion in orbits that are not nicely aligned with each other, the times between retrograde motion will only be described ...

0

Without having any experimental data at hand, I guess that most planets formed from a uniformly rotating dust disc, and thus their rotational and orbital momentum have the same sign. However, upon random tangential impacts, some of them (Venus, Uranus..) could change their original axis of rotation, and most probably it happened so early we will not find ...

3

The correct formula is actually $$M = \frac{4\pi^2 a^3}{GP^2}$$ and is a form of Kepler's third law. $M$ in this formula is the central mass which must be much larger than the mass of the orbiting body in order to apply the law. In reality the formula that should be used is $$M_1 + M_2 = \frac{4\pi^2 a^3}{GP^2},$$ where $M_1+ M_2$ is the sum of the masses ...

0

Your intuition that that this equation actually gives the mass of the body being orbited is exactly right. In general, there is no way to infer the mass of a body using any measurements of its response to gravitational forces, because in its equation of motion, $$m\mathbf a=m\mathbf g,$$ where $\mathbf a$ is the body's acceleration and $\mathbf g$ is ...

Top 50 recent answers are included