The paper is dedicated to the myth about Orion and Eos, known from the Homeric poems (Od. 5, 118–124). It has already been noted in the mythological studies that Orion and Eos of the Greek tradition are comparable to Rohiṇī and Prajāpati of the ancient Indian tradition. The names used in the two traditions differ. In particular, the etymology of the name Orion has not been reliably established; Eos finds an etymological match in the Indian Uṣás (cf. also Latin Aurōra, Avestan Ušah etc. all from PIE *H₂áu̯sōs), and Rohiṇī can be interpreted as referring to a red, glowing dawn. However, the plots of the Greek and Indian myths show striking overlaps such as a hunting motif and a love story.

Unlike such researchers as Joseph Fontenrose, who offered a detailed comparative structural analysis of the stories about Eos/Orion/Artemis ἐλαφηβόλος and Prajāpati/Uṣas, both traditions have common roots in the Proto-Indo-European mythology and poetry. In the context of the Proto-Indo-European myth, one may tentatively derive Ὠρίων, in poets also Ὠαρίων, from ὄαρ 'woman, wife': ὄαρ → *ὀαριος 'belonging to the woman' → 'the one belonging to the woman' parallel to Κρόνος → Κρονίων 'the one belonging to Kronos; Zeus'.

The Proto-Indo-European myth was based on observations of the movement of stars in the night sky, in which the constellations Orion and Aldebaran (Eos, Rohiṇī) move in close proximity to each other, which formed the basis of the story of Orion chasing the dawn. Thus, the ancient Greek and Indian traditions not only preserve traces of the Proto-Indo-European myths, but also traces of astronomical observations of Proto-Indo-Europeans.