Interstellar Nebulae: Map Border, Harvest, New Systems

[Hirnsausen]

Interstellar nebulae are not really dense at all, they could never stop engines. They are far less dense than the atmosphere of Earth, they are near-vacuum. But they could slow down ships or cause minor damage to the hull or over-heating like in a dense atmosphere. They are not dense, but they measure light years in diameter, and ships fly extremely fast, so this way overheating or hull damage or slow down could happen.

Also, make these nebulae harvestable. They are hufe, much larger that multiple star systems together, so they can never be "finished" with harvesting. ionized and neutral and molecular hydrogen, oxygen, helium, dust-alike iron and silicon and carbon particles.

Due to the giant size of nebula, I can imagine that they would be along the border of the playable area of DU, with a few outbursts/arms of them stretching inwards. Despite being the edge, they can be harvested without ever losing size.

However, as nebulae give birth to new star systems, each time when DU will expand its map of star systems, the explanation could be that the nebula border on that location has disappeared because it gave space to new star systems. Those systems would be very young, very radioactive and hostile but players and organizations can build terraforming plants to slowly transform them into more or less fully habitable planets and moons. While other players or orgs might want to destroy those terrafomers to keep some new planets unattractive to a wider mass of players...