Mining for resources is integral part of game economy. Miner is not a separate job because almost every role player can do it, all you require is equipments to do mining, than you can do it either in asteroids, or inside planets, planetoids, planet moons etc. mining is not just going somewhere and start digging, it's more of a research based work. so here your community might come handy, you can share information of research with players you want so that you can mine together and grow as community. Planets have different resources, some sectors might have planets that contain very lucrative resource and you can share that information with your faction to get strong together. As the game progresses resources will go scarce and get hostile to harvest, so you have to venture out far in the sectors or jump to another sector to get more resources.