They say not to go into deep space.
The life hazards due to meteors and even aliens appear not to be the principal concern. There's something unhealthy up there, and it crafted the local fauna into what it currently is. They have a theory about it; they call it the Space Survival Model. Trekkies would nickname it the Borg. Basically, they say that if the key part of life on a livable planet is competition for resources, the key part of life in deep space, is assimilation.

The crew of the NSS Numephoros followed a distress signal emitted from a lost cruiser, and it took them astray from known space routes. All their attempts to communicate with the distressed ship were met with a dead silence, except for the same distress signal playing endlessly, and a peculiar screech they couldn't identify. And then they faced it... the ship. The deadly alien that had taken it over was slowly wriggling on the back of the wreck and waving its metallic tentacles at the newcomer like an ominous sign of hungry welcoming.
Indubitably, the engines were slowly giving out and the alien, probably damaged, could only wave around in search for functional engines to keep propelling itself through the space abyss.

The crew would leave some questions for a later time, like whether the signal had kept being emitted despite the alien destroying the ship... or did the alien somehow manage to keep it functioning, and used it as the lantern of some sort of space abyss predator??
For now they had a job to do, and it had little to do with answering these questions.