Certainly. If you're wanting a bit more realistic planet mod, I think Novus Universum would be a good mod for you. Most of the gravity wells are a lot bigger (if still not exactly to scale), and more realistic skyboxes, moons etc. really add a lot for an astronomy buff. Sadly its a bit out of date, though its a permanent part of the Sins of a Galactic Empire mod. If you ask in the thread or the SoGE website maybe you'll persuade him to update the stand alone. Or in a few weeks I may update it if I have time.

Try the "Celestial Bodies" mod.  It has almost no changes aside from the planets and stars and adds quite a few variants with different sizes.