Reissun

Reissun is a term used in the fictional field of astrogeography to describe a periodic alignment phenomenon observed on the planet Asteria. The name derives from the Reissan language, where rei means “return” and sun refers to the star, reflecting the renewed brightness associated with the event. In standard usage, reissun denotes a coordinated alignment involving multiple natural satellites and the star, which produces distinctive optical and tidal effects during a defined orbital window.

The mechanism involves three moons entering near-syzygy with the sun during a particular phase of Asteria’s orbit. This triple alignment intensifies reflected solar light and gravitational interactions, producing a noticeable, multi-hour flash of brightness and a surge in tidal energy. The event recurs roughly every 13 to 15 years, though the exact timing depends on the satellites’ orbital resonances and perturbations from other bodies.

Observationally, a reissun is marked by unusually bright daylight for the period, higher-than-average tides along coastlines, and occasional storm intensifications. Remote sensing records show a transient shift in light spectra and a short-lived ionospheric disturbance corresponding to the alignment. In contemporary science, researchers use orbital models and space-based instruments to track the event and study its atmospheric and oceanic responses.

Culturally, reissuns have played a role in coastal calendars, navigation practices, and ritual cycles in the planet’s fictional societies. In literature and speculative science, the phenomenon is often invoked to explore questions about planetary climate sensitivity, energy cycles, and the interplay between astronomy and culture.