Asteroids which lie within interstellar space, rather than orbiting a star within the system.

Brull's direct course from Gamma Hromi II to Chorgan's base planet is 343-m-72, but Wesley Crusher tactfully suggested an alternate route to miss an asteroid field along that line. In the Delta Quadrant, one field surveyed a month before stardate 49373 yielded a form of dilithium more stable at much higher high warp frequencies than the norm, allowing Paris to break the Warp 10 barrier.