Phosphine is a colorless, flammable gas with a distinct odor resembling that of rotting fish. Its chemical formula is PH₃, and it consists of one phosphorus atom bonded to three hydrogen atoms. Phosphine is primarily used in the production of semiconductors and as a fumigant in agriculture to control pests. 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 as a biosignature gas, suggesting the presence of life on other planets, such as Venus, where phosphine was detected in the atmosphere.