[Elowan]

I've been replaying a game in order to get a handle on dealing with an alien culture. One of the things happening was puzzling me but now I think I know what's up.

Here's the situation:

I have a farpoint system that is adjacent to an empty system filled with a nebula which prevents scanning. The empty system has 3 warp points:

1) to my system
2) on the farside directly opposite my system 'gate'
3) one below mine on the same side.

In previous games - if I put a sentry fleet on the nebula side of any of the warp points - the alien fleet gets by me. If I place them on my or a normal system side of the WP - I catch them.

I suspect that they are invisible within that nebular system and sneak by. This was/is not expected by me because I thought that visual worked. That is - I have no sensors on any of my ships at this point - so I thought that i should be able to see them.

I'm new at this but it appears that a nebula 'cloaks' any ship within the system. Right?
Seems obvious - now. But I'm just checking with the experts.