As with any field of scientific study, astronomy has a long list of important terminology. So we've put together this glossary where you can check you fully understand the meaning of the common terms, as well as some of the more unusual words.

A -- B -- C -- D -- E -- F -- G -- H -- I -- J -- K -- L -- M -- N -- O -- P -- Q -- R -- S -- T -- U -- V -- W -- X -- Y -- Z

Words beginning with 'I' :

Inclination : the angle between the orbital plane of an object and the plane of reference (for example the Earth’s equator can be a plane of reference).

Inferior planets : planets orbiting the Sun inside of Earth’s orbit.

Infrared : an electromagnetic radiation with wavelength ranging from the edge of visible light at 700 nm to 1 mm. It has longer wavelengths than visible light, but shorter ones than microwaves.

Resources :

To support the quizzes in each section, we've put together some extra resources to provide further information: