TITHONUS' STAR SYSTEM

Eos if the sun. Its planets are...

1.Urion
2. Cephalus
3. Cleitus
4. Astraeus
5. Tithonus

Four comets come periodically almost together, called by Earth astronomers Boreas, Notus, Zephyr and Eurus. They have a close orbit around the sun before they return to space and are VERY regular. They have a heterodying effect on Eos, causing increased flares, radiation, etc. once every 75 years, which is how often they come. 95% of life on Tithonus was killed during those two years when the flares,etc. are so bad, which is why no natural mechanism to limit lifespan was needed. It caused hurricanes, dense fogs, forest fires, etc. Very few lifeforms lived through two such flare times. Some have speculated that the four "comets" are the remains of a shattered world in a skewed orbit.

Of course, once the lifeforms became intelligent and could shield themselves, things changed...