Here is another suggestion for comets:
Basic game concept:
Comets come from the interstellar space or Deep space beyond the heliosphere of a solar System, there best goodies are burried beneath layers of “dirty ice”. To get there they have to be forced out from under the thick shell of dirty ice.
Comets are gigantic they are between huge asteroids and moons in the size charter.
Comets aren’t stable like asteroid belts less than anomalies they appear once per month or even less and stay only for a specific time - three to seven days - in a System after this time they disappear into the interstelar realm again.
a coment has two or three layers of different ores.
Layer one is dirty ice this is a ice that when refined returns ice products mixed with tritanium.
Layer two is composed of highsec ore variants.
Layer three or the core is composed of variants of null ores as well as moon ores.
While the upper layer or outer shell can be excavated with a simple ice harvester, to gain Access to the deeper layers the comet has to be blown open. Depending on the place the blowing operation manages to get to layer two or layer three creating a belt of ice asteroids and asteroids of the ores within layer two or the core.
The blowing Operation is done by anchoring a comet drill a mobile depot sized structure at close to the Comet and Setting it of, the Comet drill evaporates during the blow out event. The drill itself can reach a certain level of deepness below the crust, maybe five kilometers.
For a mining team to find a good spot a new Kind of survey scanner is needed or a new survey scanner probe that is deployed on the comet. It revels in a d-scan like angle what can be found until a deepnes of Five Kilometer at that specific place.