1. Astronomy: In astronomy, a black planet is a hypothetical planet that primarily consists of rocky or metallic material and reflects very little light. Because of their low reflectivity, such planets would be hard to detect.
2. Science fiction: Science fiction literature and other creative works often feature fictional black planets. In these portrayals, black planets may have various characteristics, such as being extremely dark, located far from a star, or associated with alien life.
3. Metaphorical or symbolic: Some artistic, literario, or symbolic contexts us the term "black planet" as a metaphorical representation of various ideas or emotions, such as mystery, darkness, or isolation.