I want to create a solar system like the one shown in magic leaps video at 0:18 seconds
[video]Magic Leap | Demos: Everyday Magic with Mixed Reality - YouTube
What would be the best way to go about doing this?
Would it be better to create a single blueprint containing every plant and animations or would it be better to do separate blueprints for each plant and parent them so they have to stay together?
I would make a blueprint to control a planets size and spin, then replace the planet with the right textured one so there would be, yeah a few, not one master one. but that’s just how I’d go about it. You’ll want a global scale of the planets and the size between them, so maybe all in one…
I would recomend looking at some of the available assets on the market place as is. The business contract states that when you purchase Users are free to modify any content they purchase from the Marketplace. Mean that it is a teaching tool plus your able to expand what the original authur couldnt do. Read up on the business section for furthure detail.
The planets are essentially spheres. There are lots of diagrams that give relative sizes of the planets to each other, so that is easy to find. Nasa publishes all of it’s images (there is a new high res image of Jupiter) online, because it is public domain, i.e. we own it.
Therefore you don’t actually have to pay anyone for the texture maps to the planets and spheres are about the easiest thing you can make.
The sun is a different beast. You can start with the imagery that Nasa collects of the sun, but it would involve a lot of particle effects to get the look similar to the Leap video, this takes practice and patience and a lot of work exploring the particle side of UE4.
So, all that said, i’d keep my blueprints separate and make a planet blueprint library. They can all spin around the same axis point by even modeling them in Maya (or the modeling software of your choice) in position so that their center of axis is always at the middle (the sun) and then you can just spin them around that.
Actually, now that i think on that, I would probably do that in two steps.
1 ) I’d make a planet parent that is offset from the center of world space.
I'd export this as the planet solarAxis or something like that. i.e. JupiterSolarAxis
2 ) I’d keep my planets at center of world so they can easily be revolved from their center axis as well.
Export this as Jupiter
in UE4 I would then parent my Jupiter to JupiterSolarAxis, and make sure it was offset to the location of Jupiter that i had diagrammed out in Maya. *I would probably make a smaller version of Jupiter that wouldn’t render as my target.
Then you can build your blueprints one planet at a time and make the animations you want and populate the scene with the planets in space.
i hope that is helpful
-finn
At around 01:15 in the video, you can see a miniature solar system (orrery) by Epic.
All Blueprint magic 
(08:15 in the video)