Final answer:
The sun reversing course in the sky in relation to the House of Atreus is not detailed in myths; Greek mythology often used divine actions to explain celestial phenomena, and characters from the myths are represented as constellations.
Step-by-step explanation:
The myths associated with the House of Atreus do not specifically mention the sun reversing course in the sky. However, in Greek mythology, various astronomical phenomena are often explained through the stories and actions of gods and heroes. In some myths, these celestial patterns and anomalies are the consequences of divine favor or wrath. For instance, in Greek legend, constellations were reminders of stories or penalties imposed by the gods. Perseus, associated with the sun, is depicted as a hero who releases the dawn after his struggle with darkness. Stars like Algol in the constellation of Perseus, which represented Medusa's head, were thought of in terms of their brightness changes, perhaps conveying divine messages or intrigue.
Constellations themselves, such as Cassiopeia and Andromeda, were seen as immortalized characters in the stars, serving as reminders and often associated with divine actions or reactions, such as Cassiopeia's vanity leading her to rotate perpetually around the celestial pole.