September 15, 2020

Anna Murray 

An international team of astronomers, including researchers from Britain, Japan, and the US, announced their discovery of phosphine in the clouds of Venus on September 14. The rare gas molecule is only made industrially or by microbes that thrive in oxygen-free environments on earth. Thus, their discovery may be the first leading evidence of extraterrestrial life in the solar system.

The team detected the unique spectral biosignature of phosphine using the James Clerk Maxwell Telescope (JCMT) in Hawaii in 2017 and the Atacama Large Millimeter/submillimeter Array (ALMA) in 2019. The researchers published their findings in two papers, "The Venusian Lower Atmosphere Haze as a Depot for Desiccated Microbial Life: A Proposed Life Cycle for Persistence of the Venusian Aerial Biosphere" in Astrobiology journal on August 13 and “Phosphine gas in the cloud decks of Venus” on the science journal Nature Astronomy on September 14.

The lead author, astrobiologist, and astronomer Jane Greaves of Cardiff University was stunned when she first spotted phosphine in observations using JCMT in Hawaii. The discovery was then confirmed by means of ALMA, a more sensitive radio telescope, in Chile.

Another associate scientist of the team, molecular astrophysicist Clara Sousa Silva from Massachusetts Institute of Technology, stated it was exciting and extraordinary to detect phosphine on Venus as a biosignature gas of non-oxygen-using extraterrestrial life on the planet.

It is great to discover the traces of phosphine in the hellish, heavily acidic atmosphere of Venus. However, experts acknowledge that confirming the presence of extraterrestrial life needs a lot more work.

Photo:Webshot.