I see what you mean. I’m not much of a builder, but I’m ninety-nine percent sure roblox doesn’t support shaders like such. You could put a particle emitter on the dark side of the planet, with no velocity, infinite lifetime, tiny size, and relative to the world, if you want the planet to spin eventually. The alternative option is placing parts that disappear on the light side, and show on the dark side, each with tiny size and neon material. Un-anchoring them and welding them to the planet will make them spin correctly.
Again, I’m a scripter, so I’m likely not the best source of advice. Worth a shot, though.
U could make color map transparent using photo editor and duplicate mesh and change it to neon and increase size of other mesh and add ur surface appearance in this mesh