Phosphine gas

Subject: Science and tech

Context:

An announcement by an international team of astronomers about the discovery of phosphine gas in the atmosphere of Venus triggered global excitement.

Concept:

• Phosphine is a colourless but smelly gas, known to be made only by some species of bacteria that survive in the absence of oxygen.
• Scientists have discovered this chemical which is known to be produced only through biological process, and not through any naturally occurring chemical process.
• There are some other ways in which this chemical might be produced, for example, in the underbelly of volcanoes or meteorite activity, but that would have shown in much lower concentrations. In any case, scientists have ruled out all those kinds of known possibilities which could be attributed for the presence of that gas.
• This is the most credible evidence yet for the possibility of life away from Earth
• The finding can further ignite interest in space missions to Venus. Missions to Venus are not new. Spacecraft have been going near the planet since the 1960s, and some of them have even made a landing. In fact, the Indian Space Research Organisation (ISRO) is also planning a mission to Venus, tentatively called Shukrayaan, in the near future.