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 'U' :

Ultraviolets (aka UV light) : electromagnetic radiation with a wavelength ranging from 10 nm to 400 nm. It is shorter than visible light and makes up 10% of the Sun’s output.

Umbra : the darkest part of an object’s shadow. For a spherical astronomical object the umbra will form a cone.

Resources :

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