- A planetary nebula is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives.
- The Light Fantastic (Wikipedia)
The Light Fantastic is a comic fantasy novel by Terry Pratchett, the second of the Discworld series. It was published on 2 June 1986, the first printing being of 1,034 copies. The title is taken from L’Allegro, a poem by John Milton, and refers to dancing lightly with extravagance.