Era beginning/end
Atmospheric loss has been decelerating over the Primordial Eon at a slower rate than the Preorganic, but some of this loss still contributes to a noticeable thinning of the cloud layers. Atmospheric density is also the lowest it has ever been so far due to overall less atmospheric weight. The very end of the Primordial Eon is marked by the very first time Lite's solar energy reached and began reacting with the planet's rocky and watery surface, producing new chemicals from the atmosphere and the salts and other precipitates on the rocks that hadn't been there before.