Perihelion Event
From Alpha Centauri Wiki
When Planet’s orbit takes it closest to Hercules (Alpha Centauri B) the increased temperature on Planet stimulates wild native lifeforms. Existing and newly spawned lifeforms gain +1 to their life cycle and the effects of ecological damage are doubled causing more native life to spawn. Native lifeforms bred in captivity are unaffected.
Perihelion lasts 20 years and occurs every 80 years. The effects are first predicted for the perihelion starting in 2190.
