Phosphine is a colorless, flammable gas with a distinct odor resembling that of rotting fish. Its chemical formula is PH3, indicating it consists of one phosphorus atom and three hydrogen atoms. Phosphine is primarily used in the production of semiconductors and as a fumigant in agriculture. In nature, phosphine can be produced by anaerobic bacteria during the decomposition of organic matter. It has gained attention in astrobiology due to its potential presence in the atmospheres of gas giants like Jupiter and Venus, where it may indicate biological activity.