There are six chemical elements that life on Earth depends upon. A new study, however, suggests one of these may not be abundant in the universe – possibly dampening hopes of other life.
Led by Cardiff University in the UK, the research was presented this week at the 2018 European Week of Astronomy and Space Science.
Using the William Herschel Telescope at La Palma on the Canary Islands, the team observed the infrared light from a supernova remnant 6,500 light-years away called the Crab Nebula. They also studied another, called Cassiopeia A, 11,000 light-years away.
In particular, they were looking for the light from iron and phosphorous. The latter is said to be essential to life on Earth, the others being carbon, hydrogen, nitrogen, oxygen, and sulfur. Cells use the compound adenosine triphosphate (ATP) to store and transfer energy, which is dependent on phosphorous.
They found that while phosphorous was created in supernovae, its levels fluctuated quite a bit between the two that were studied. This could make it difficult for life to form on planets where the element is not abundant.
“The route to carrying phosphorus into new-born planets looks rather precarious,” Dr Jane Greaves, who presented the findings, said in a statement wonderfully titled, "Paucity of phosphorus hints at precarious path for extraterrestrial life".
“We already think that only a few phosphorus-bearing minerals that came to the Earth – probably in meteorites – were reactive enough to get involved in making proto-biomolecules,” she added.
If supernovae are the sole source of phosphorous, which then travels through space in meteorites, a planet near the wrong supernova – one with low levels – could find itself lacking the ingredients for life.
The team are going to observe other supernova remnants to see if their phosphorous levels also vary so much. But if they do, it might be bad news for the chances of a given world being able to support life.
“In that case, life might really struggle to get started out of phosphorus-poor chemistry, on another world otherwise similar to our own,” said Dr Greaves.
Other studies have also been looking for ingredients of life elsewhere in the universe. Last year, it was announced that methyl isocyanate – a molecule consisting of nitrogen, carbon, and oxygen – had been found around a star, a boon for the prospects of life.
As of yet, though, we don’t really know how life on Earth arose, much less if it is possible elsewhere. But finding ingredients like these, or a lack thereof, could tell us more about what we could expect to find on planets beyond our Solar System.
