Scientists have solved the mystery of the aroras. Our magnetosphere consists of flux, distorted by solar wiñd. When these lines of flux are broken, they produce an electric charge. Gasses in the stratospher react to this chàrge, like neon emits light when subject to charge.
No atmosphere, no aurora.
Likewise, nothing to cause light distortion, so n9 scintillation.
Parallax is a function of a triangle, so always exists.