I don't know if this is a bug, an improperly designed feature, or just something that nobody noticed or what but Dead Asteroids are extremely annoying when you're trying to get trade income. To sum it up the only planet type in the game that can break your longest trade route (which determines your trade income to a large extent) is a Dead Asteroid. Unless you have the +4 logistics research there is no possible way to get a trade route to pass through one of those planets, even through it'll go through asteroid belts, stars, and gas giants without any difficulties.

I suspect that the reason is a line of code somewhere that's used in determining the longest trade route which says something along the lines of 'If planet is colonizable and doesn't have a trade route then you can't go through it'. The problem is that certain planet types (only dead asteroids in the default game, but I'm sure someone, somewhere has introduced new types with no logistics) don't have any space for a trade route, without anything else built, and so act as impentrable walls to your trade route, which is irritating (play a game on doppleganger, enjoy the max length of 3 for your routes when you have planets that are 5 apart. Not a huge difference, but enough to be irritating) and doesn't make any sense.

Therefore I'd like to request that this at least be looked into, and that, hopefully, a simple method of making it so that planets have to be colonizable, not have a trade route, and have >0 max logistics in order to break a trade route.