In ancient Greek mythology, Astraeus is a second-generation Titan, descended from Crius and Eurybia. Appropriately, as god of the dusk, Astraeus married Eos, goddess of the dawn. Together as nightfall and daybreak they produced many children who are associated with what occurs in the sky during twilight.

They had many sons, including the four Anemoi ("winds"): Boreas, Notus, Eurus, and Zephyrus and the five Astra Planeta ("Wandering Stars", i.e. planets): Phainon (Saturn), Phaethon (Jupiter), Pyroeis (Mars), Eosphoros/Hesperos (Venus) and Stilbon (Mercury).
He is also sometimes associated with Aeolus, the Keeper of the Winds, since winds often swell up around dusk [source - Wikipedia]

In attempting to convey the feeling of dusk, I use the distinctively dark & introspective qualities of the ancient Greek Hypodorian Mode - misnamed the 'Aeolian' mode by scholars during the Middle Ages, this mode consists of 2 conjoined tetrachords, forming the equivalent intervals as A-A on the white notes of the piano (but heard here, in the pristine, pure focus of just intonation). I feature a repetitive motif in the left hand later in the piece, to evoke the chirping rhythm of cicadas at dusk. I also feature the use of harmonics, to musically evoke the shimmering rays of the setting sun.