Very nice! Of course, not to scale or you wouldn't really see anything, the planets would be tiny compared to the sun and so far away that you wouldn't be able to see them all. And it looks like currently their orbits are circular, not elliptical, but it's just a representation. I like that you can click on each planet and the camera follows it, would be nice to have a little pop-up window displaying some info about the selected planet such as name, mass, how many moons it has, and so on. That's quite easy to implement. I'd like to see more control over the main camera too, such as being able to orbit, pitch and yaw to look at the solar system from different angles. The mini-map is a nice touch. Overall, great job, excellent work. Where did you get the visuals? Did Unity provide a free pack or did you get it on the Unity Asset Store?
~John