Kupalo
(Old Church Slavonic) - IPA(key)
Kupalo (/kuˈpɑːloʊ/) is a subsatellite to the moon Mavka. It is a barren rock with little geological distinction to speak of. Across its surface are a number of wavy mountain ridges and open plateaus, between which run valleys. It is notable for its extremely short gravity well, which makes escape from its surface a trivial task.
Nomenclature
From East Slavic folklore, Kupalo is a character in the legend of the Mavka. According to legend, Kupalo and Kostroma are a long-lost brother and sister, and are unwittingly entered into a star-crossed love when the gods trick them into marrying each other. After revealing their duplicity, Kupalo throws himself into a nearby fire, and Kostroma drowns herself in a lake. However, Kostroma does not die, and is instead reborn — perhaps by Veles' doing — as the first Mavka, a type of spirit associated with mountain rivers and forests. Thereafter, she is cursed to roam around the forest lake forever, charming young men who wander across it and dragging them down in the water. She believes all the while that they are Kupalo returned to her, only becoming aware that they are not once it is too late.
The gods relent after seeing their revenge was too cruel, and turn the spirits of Kostroma and Kupalo into a flower of blue and gold known as Kupalo-da-Mavka — blue for the forest lake in which Kostroma drowned herself, and fiery yellow for the fire in which Kupalo burned.