JackDole , Yes, the third example seems impossible, at least not with one epicycle. I attemped it, but the planet is slowest near the ellipse focal points. If you imagine the epicycle's (I used a barycenter) orbital period to be 1 and that of the planet -1, then you get an ellipse with the Sun in ...

JackDole , I cannot outright claim that your approach with the first configuration is incorrect either. But unlike your second gif, the binary stars in the video have retrograde orbits. (Which should not be a problem in SE at all anyway)

The next examples: To me the green market orbit of the two ...

I might have been overlooked 

Sorry An'shur -- I didn't overlook it, but I don't know of the answer offhand.  I may try to figure it out when I have the opportunity.

Nevermind, I'll wait.

I came across an interesting video. I am wondering how could I calculate the orbital period of the configuration at 3:32. I know all of these are three body orbits which are unstable, but the one I am interested in appears to be doable in Space Engine.
[youtube]8_RRZcqBEAc[/youtube]

Edit:
https ...

Terraformed Mars look-alike

I came across an interesting video. I am wondering how could I calculate the orbital period of the configuration at 3:32. I know all of these are three body orbits which are unstable, but the one I am interested in appears to be doable in Space Engine.
[youtube]8_RRZcqBEAc[/youtube]

Edit:
https ...

Epicycles are also "right" if you keep adding enough of them
I came across this nice illustration how any orbit can be described by epicycles:
[youtube]QVuU2YCwHjw[/youtube]
Wow...

Speaking of epicycles, I created this impossibility.
https://imgur.com/a8wccle.gif

https://i.imgur.com ...

A height map of Earth with Greenland and Antarctica without ice would be very interesting. I do not mean procedural Earth with tweaked weather, which would leave these two landmasses as 2-4k high plateaus.

I mean something like this:
https://upload.wikimedia.org/wikipedia/commons/8/8b ...

A question: If the bodies are really massive (merged?) black holes, could the slopes down from L4 and L5 be so steep so these points become a kind of massless "white" hole?
midtskogen , that is an amazing question. Off hand, my gut feeling is that it cannot, but I do not know for sure! I will ...

Nice!

Thanks!

it is even possible for an object to orbit around... something that has no mass at all! (Here, there be [s]dragons[/s] Lagrange Points).
Could I place the Moon (or a moon in general) to the Lagrangian point between the planet and the parent sun so it casts a permanent solar eclipse shadow on the ...

20886 Is the Moon more strongly atracted to the Sun than to Earth?
Reading this question, I though that the obvious answer is no. Moon should be more attracted to Earth, since it orbits it, instead of the Sun.

So I checked the gravitational force calculator . Moon is attracted to Earth with the ...

What if giant planets were closer to the Sun with other planets as their moons? The answer is 12 terraformed worlds, one artificial and Earth tidally locked to Jupiter, with the farthest point from the core, Chimborazo, having Jupiter directly overhead. Added to my database.

In most cases, neutron stars and black holes seem to be accompanied by a brown or red dwarf if in a binary system. The rarest binary star arrangement I stumbled across once was a neutron star (or a black hole) with a main sequence F class star.

Has anyone ever found a multiple star with more than ...

It also lasted long. Formed in the German Alps and over the night, traveled about 700 kilometers northeast before dissipating in the morning.