- Life Objects
- Class 1 Catalog — Stable
- Class 2 Catalog — Oscillating
- Class 3 Catalog — Moving
- Class 4 Catalog — Infinite
Two or more spaceships can be located next to each other such that their sparks interfere. In some cases, these combinations produce actual objects, while others are simply close together without actually interfering (pseudo-objects). There are six possible ways to combine the three types, but one (lightweight + lightweight) only produces a pseudo-object.