Ly?
9.461 x 1015 Meter
1 AU?
= 1.496 x 1011 Meter
Definition "star"?
=Large, glowing ball of gas that generates heat an light thgrough nuclear fusion in its core.
Definition "planet"?
= moderately large object orbiting a star & shining primarily by reflecting light from its star.
According to IAU: Object is a planet if it:
Definition "Exoplanets"?
= Planet, that:
Definition "Moon / Satelite"?
= Object orbiting a planet / one object orbiting another.
Definition "asteroid"?
= relatively small and rocky object orbiting a star.
Definition "Comet"?
= relatively small and ice-rich object orbiting a star.