He explained this decision in a letter to Joseph Banks: In the fabulous ages of ancient times the appellations of Mercury, Venus, Mars, Jupiter and Saturn were given to the Planets, as being the names of their principal heroes and divinities.
Explicou a súa decisión nunha carta a Joseph Banks: Nos fabulosos tempos da antigüidade os planetas recibiron as denominacións de Mercurio, Venus, Marte, Xúpiter e Saturno, como os nomes dos seus principais heroes e divindades.