Discovery of Phosphine on Venus - What Does It Mean?

A Nature Astronomy paper in September, titled "Phosphine gas in the cloud decks of Venus", has led to an exploding curiosity toward our planetry neighbor and increasing speculation of alien life forms on Earth's "hellish" twin. However, the news might have also got you scratching your head: why does the finding of a single, inorganic compound has any connection to life beyond Earth?

The international team of scientists behind the research first spoted phosphine's molecular "fingerprints", a unique pattern in spectral absoprtion, back in mid-2017, using the James Clerk Maxwell Telescope in Hawaii. In 2019, a study using the ALMA telescope in Northern Chile confirmed the earlier findings, and also determined the atmospheric concentration of the compound to be about 20 parts per billion (ppb).

Phosphine (PH₃) is a flammable, odorless, and highly toxic gas. It was first artificially produced in the lab in the late eighteenth century by chemist Philippe Gengembre, who heat up white phosphorus in a solution of potassium fertilizer. The synthesis of phosphine through inorganic reactions is possible but its synthesis require a huge input of energy. And given the raw materials and the environmental conditions on Venus, scientists found it unlike for phosphine to be so concentrated without any involvement of biological processes. 

Therefore, the researchers concluded that the discovery of phosphine in the upper atmosphere of Venus could be an indication of "the presence of life" on the planet.

Source: Seeker via Youtube