Astrophysically-Evading Phosphorus: A Crucial Element for Terrestrial Life
Phosphorus, often overlooked as the 15th element on the periodic table, is fundamental to life as we understand it. This element serves as the structure's backbone in DNA and RNA, as Natalie Hinkel, a planetary astrophysicist at Louisiana State University, explained to me via email. But that's not its only role; phosphorus also acts as the energy currency in nearly all metabolism, such as adenosine triphosphate (ATP), moving proteins and lipids in and out of cells.
Being highly reactive, phosphorus is never found in its pure form on Earth. Instead, it's bonded with minerals or molecular compounds. Apart from its role in cell membranes, bones, and teeth in humans and animals, it's crucial for microscopic ocean plankton. Although astrophysicists are still debating its formation process within our Milky Way Galaxy, they agree that current galactic chemical evolution models produce less phosphorus compared to observations.
Phosphorus stars, primarily observed in the Milky Way's inner galactic halo and thick disk, suggest that the process responsible for their enrichment is location-independent, revealed Maren Brauner, a PhD student at Spain’s Instituto de Astrofísica de Canarias and the Universidad de La Laguna.
The beginning of phosphorus is quite explosive, as Maria Lugaro, an astronomer at Hungary’s Konkoly Observatory, explained. It's formed by nuclear burning in stars significantly more massive than the sun that ultimately end their lives in a core collapse supernova explosion. Stars like our sun have a relatively high amount of phosphorus, making it essential to have a better understanding of their prevalence around nearby solar type stars.
Detecting phosphorus is challenging, as its spectra can only be observed in the near-infrared or ultraviolet spectrum's rare high-resolution observations. The slight underestimation of observed phosphorus amounts in normal stars and the presence of phosphorus-rich stars in the Milky Way are puzzling for researchers.
[1][3][5] suggest that while phosphorus is not directly produced in stars through primary nuclear fusion processes, its formation might occur through secondary nucleosynthetic processes. The abundance of this element in the Milky Way Galaxy is not explicitly addressed in the provided sources, but scientists acknowledge its importance in life and planet formation. However, its abundance might be less significant in certain regions compared to other elements.
Despite the challenges in measuring the interior or surface composition of small earth-sized planets beyond our Solar System, the role of phosphorus in the hunt for life beyond our solar system is significant. If stars have practically insignificant amounts of phosphorus, their planets could be inhospitable, potentially ruling out the possibility of life altogether.
The text mentions that phosphorus, though not directly produced in stars through primary nuclear fusion processes, might form through secondary nucleosynthetic processes (sentence 1). Innovations in science and technology, such as advancements in telescope technology, could help us better understand the abundance of phosphorus in different stars and its potential impact on extraterrestrial habitability (sentence 2).
