Matter in the core of the Sun is completely ionized. The Sun rotates approximately once per month. The photosphere is the visible surface of the Sun. The Sun appears to have a surface because the gases suddenly become opaque to light, meaning we cannot see further into the interior. The largest observed parallax for a star is almost one second of arc.
Planetary orbits are nearly in the same plane.
Planetary orbits are all nearly circular. All planets rotate in the same direction as they revolve. The first step in the formation of the solar system was the collapse of a rotating interstellar cloud. The largest asteroid, Ceres, has a diameter approximately that of the Earth. Galileo first showed that comets are extraterrestrial.