(astronomy) Of, or relating to planets, or the orbital motion of planets. / Of, or relating to the Earth; terrestrial. / Of, or relating to the whole Earth; global. / (of a gear train) epicyclic

A planetary nebula.

plural of planetary

That branch of astronomy that deals with the planets of the solar system.

(astronomy) a ring of dust, moonlets and other matter that orbits a planet (such as Saturn) as a flat disc; gaps in the ring are due to the presence of shepherd moons

A system of gears that has a central gear wheel (sun gear) around which others (planet gears) rotate, often within an outer ring.

(astronomy) A nebulosity surrounding a dying red giant, consisting of material expelled by the star.

plural of planetary ring

Alternative spelling of extraplanetary

A group of smaller bodies (such as planets or asteroids) that orbit one or more stars.