Phosphine gas could be key to identifying alien life

Phosphine is a chemical compound between phosphorus and hydrogen, the chemical formula is PH. This is a colorless, highly toxic gas with a garlic odor. Recently, scientists suggested that this gas could be the typical compound for life on distant planets.

How do you search for otherworldly life? While gases that we normally associate with life, like oxygen or methane, are commonly found on other planets, that doesn’t necessarily indicate that living things are present there.

Phosphine gas could be key to identifying alien life
Phosphine’s existence is believed to be an opportunity to detect alien life.

The puzzle of fluctuating methane levels on Mars, for example. The Curiosity rover detected high levels of methane, but scientists think this is likely caused by geological, not biological, forces. So the presence of these gases does not give a positive indication of the presence of life.

On Earth, oxygen is a really impressive sign of life, Dr. Clara Sousa-Silva, a scientist in MIT’s Department of Earth, Atmospheric and Planetary Sciences, explained in a statement. .

Some things other than life also produce oxygen. This is why research is focused on trying to identify signs that can only come from life. It’s important to consider strange molecules that may not be produced very often, but if you find them on another planet, there’s only one explanation.

Phosphine is one such unusual molecule. It is found in the Earth’s atmosphere, although only in very low concentrations. That’s probably also good for us as it has a particularly foul odor that is often compared to garlic or rotting fish. It is also highly toxic, attacking the respiratory system, and it has been known to cause death by accidental exposure.

Despite its toxic nature, however, phosphine can be an invaluable biomarker for life. A research team from MIT has found that phosphine can only be produced in an anaerobic (oxygen-independent) environment . The team looked at as many phosphine sources as they could think of, including chemical reactions and geological anomalies.

Future examinations of exoplanets using instruments like the upcoming James Webb Telescope will be able to detect the presence of phosphine, even in small quantities, from up to 16 light-years away. bright. If such a signal were detected, it would be the strongest indication of the presence of life on another world.