Ennth
this planet was a colony world which seemed to resist any attempt at settlement. The first colonists established a series of outposts on the world, and soon learned that the planet's single moon had a wildly elliptic orbit. This orbit brought it close enough to Ennth every eight years for it to skim through Ennth's atmosphere. This proximity resulted in incredible tidal and seismic stresses that tore the world apart every eight years. The colonists fled to space stations in orbit to survive the devstation, but their strength and will led them to return after the moon had passed and rebuild their settlements.