- Low gravity
- Tectonic tidal pattern
A small but dense moon (0,3 G) orbiting a blue colored gas giant about the size of Jupiter with an irregular proto-ring system and way to many moons. The gravity of the large planet is so intense that it pulls at the outer crust of the moon causing a tectonic tidal pattern. A day at the moon is equal to 41 earth days so every 20,5 the tectonic tide causes ruptures of the surface crust and volcanic eruptions. Most of the planet is covered in ice under which is a liquid ocean with occasional island chains dotting out of the ice. On the tide the underwater volcanoes break up the ice and great steam plumes erupt as high as 500 km ejecting water into orbit.
The planet has evolved a primitive biosphere. Mostly there are living things in the deep oceans near geothermal hot spots. But a species of microbial lichen colonies has adapted to grow very fast on the surface. A species of omnivorous marine crustaceans has evolved to feed of the lichen. On the tectonic tide when the ice sheet ruptures the swarm upon the surface in a feeding frenzy. They scrape the lichen of the ice and rocks with claws that have evolved for the task and gorge themselves for three days. Then they descend back int the deeps when the geysers die down just before the ice sheet closes again. In three days the crustaceans almost clean the surface of lichen but it is fast growing and in 17 days it mostly covers the surface again. Such is the cycle of life.