APOD: 2020 September 15 - Biomarker Phosphine Discovered in the Atmosphere of Venus

Good morning, Rallypoiint. Today's Astronomy Picture of the Day (APOD) is titled "Biomarker Phosphine Discovered in the Atmosphere of Venus." A biomarker is a measurable indicator of some biological state, process, or condition. Phosphine (PH₃) is a colorless, highly flammable, and toxic gas. The most likely source of phosphine is the decay of organic matter, and phosphine has been detected in the atmosphere of Venus.

Why is this significant? When exposed to ultraviolet radiation (e.g. sunlight), phosphine is quickly consumed by water and carbon dioxide. In order for it to be detected then, some process must be at work to replenish it. PH₃ is associated with anaerobic ecosystems on Earth, which may be indicative of life elsewhere. Today's featured image of Venus and its thick clouds was taken in two bands of ultraviolet light by the Venus-orbing Akatsuki, a Japanese robotic satellite that has been orbiting the cloud-shrouded world since 2015.