Sometimes a planet's native inhabitants aren't even aware of some of these cycles. Blitrete was a Yexoden that passed through a debris field every 27,000 years. This would trigger skyfalls of toxic chemicals that would supercharge the growth process of slime molds which would then reach gargantuan sizes and suck out all available nutrients from the land around them. This caused famine all over the planet. Some of the slime molds grew so large that they even engulfed cities. 

The previous time it had happened, all of the sapient species of Blitrete were still in a prehistoric age. 27,000 years later they had interplanetary travel but a lackluster space observation network. Nobody had a space program advanced enough to deal with anything like this. 

Luckily, a good deal of the planet survived. The inhabitants eventually developed a network that could better monitor this kind of situation. They have a prototype for a sort of atmospheric mesh that could filter out the chemical next time the planet passed through the field. It'll be about 26,800 years before they'll need it but it's best to be prepared.