Creating life from an organic soup can be quite complex, requiring a diverse range of ingredients, all coming together in the right conditions.
While the precise conditions are still a topic of debate, there’s a strong idea of the periodic table elements needed for this process.
One crucial element, phosphorus, has been discovered on the edges of the Milky Way galaxy; an unexpected location. This discovery challenges the traditional understanding of how phosphorus is produced, with such large stars responsible for its creation not typically found in this area of the galaxy.
According to astronomer and chemist Lucy Ziurys of Arizona State University and Steward Observatory, “To make phosphorus, you need some kind of violent event,” says astronomer and chemist Lucy Ziurys.
The discovery of phosphorus in an area far from massive stars or supernova remnants suggests that there may be alternative methods for producing this essential element for life.
When the Universe’s first atoms congealed from the primordial plasma, they were mainly hydrogen and a bit of helium; other elements came along much later as a result of the formation of stars.
The elements a star produces depend on its mass, influencing the fusion reactions that occur within. These reactions can result in forming elements such as oxygen, nitrogen, lithium, and beryllium, depending on the star’s size.
Phosphorus, although not part of the known stellar fusion chains, is believed to form during supernova explosions.
Supernova explosions, typical of high-mass stars, have the additional benefit of dispersing heavy elements into space, enriching the interstellar medium to support the development of new stars and celestial bodies.
The discovery of phosphorus in a cloud known as WB89-621, 74,000 light-years from the heart of the Milky Way, raises intriguing questions.
“The phosphorus we detected is at the edge of the galaxy, where it shouldn’t be,” says chemist Lilia Koelemay of Arizona State University.
Two possible explanations for the presence of phosphorus in this unexpected location have been proposed. One involves the galactic fountain model, which suggests that elements are transported from the inner regions of the galaxy to the outer regions by supernova explosions.
However, the alternative model, which proposes that less massive stars can produce phosphorus through neutron capture in the region around their core, has gained attention following this discovery.
The fact that phosphorus has been found far from any supernova source supports the concept of phosphorus formation through a less massive star’s process.
For a planet to be habitable to life as we know it, all the NCHOPS elements – nitrogen, carbon, hydrogen, oxygen, phosphorus, and sulfur – need to be present, and their presence defines the galactic habitable zone,” Ziurys says. “With our discovery of phosphorus, all of them have now been found at the edge of the galaxy, which extends the habitable zone all the way out to the galactic outskirts.”
This discovery presents an exciting opportunity to expand the search for extrasolar life, as it suggests that phosphorus availability in the universe could be much more widespread than previously thought.
The research has been published in Nature.
