Scientists have recently detected phosphine on a brown dwarf known as Wolf 1130C, reigniting debates about this mysterious molecule’s potential implications for life beyond Earth. This finding comes on the heels of vehement debate over the sensational allegations regarding phosphine. Many are arguing that it constitutes proof of life in the atmosphere of Venus.
Phosphine, PH 3 , is a synthetic chemical compound composed of phosphorus and hydrogen. Scientists are particularly interested in it because, on Earth, biological processes can be the primary source of this compound. In 2020, scientists reported a detection of phosphine in the clouds of Venus, sparking excitement and speculation about extraterrestrial life. Recent discoveries from Wolf 1130C bring thrilling new twists to the debate over phosphine. If confirmed, this finding would revolutionize our interpretation of its relationship to habitability.
The Significance of Phosphine
Phosphine has recently been discussed as a potential biosignature in the search for extraterrestrial life. We’ve found so far that microbial life is the only connection that ties it to Earth. You might think you have it cornered in places like bogs and the alimentary canal of ruminants. Used with permission from An artist’s impression of phosphine phosphine floating in Venus’ atmosphere. If confirmed, this finding would imply that the planet’s high altitude upper atmosphere could harbor microbial life.
The detection of phosphine on Wolf 1130C, a brown dwarf with a surface temperature around 320°C, complicates this narrative. While the presence of phosphine in different celestial bodies showcases its potential ubiquity, it raises critical questions about its formation mechanisms in environments that are vastly different from those found on Earth.
Characteristics of Wolf 1130C
Wolf 1130C is an interesting celestial object, though of a different variety. Wolf 1130C is a brown dwarf. Unlike stars, brown dwarfs lack stable nuclear fusion and are typically much cooler. Some young and massive brown dwarfs can reach temperatures of 2,000°C. In contrast, Wolf 1130C is cooler, allowing it to be a fascinating subject for ambient temperature comparison when studying planetary atmospheres.
This specific brown dwarf is old and has low metallicity, meaning it has low concentrations of elements heavier than helium. Researchers think it could be due to any of these factors, which have all been proposed to explain the unexpectedly high phosphine levels. Notably, the chemical compound fits like a glove with models that predicted its presence in such environments. Yet the varied, sometimes contradictory explanations for phosphine levels on each celestial body still leave us scratching our heads.
The detection calls into question current models of how phosphine is produced in gas giant atmospheres and in other brown dwarfs. Now, an international team of scientists led by astrobiologist Sarah Hörst of Johns Hopkins University have detected phosphine on Jupiter. The amounts detected there aren’t always indicative of the molecule’s presence in Wolf 1130C or other gas giants.
Implications for Life Beyond Earth
Finding phosphine on Wolf 1130C brings up entirely different questions. It provides the first molecular evidence that it may not only be tied to biological processes, upending long-held beliefs. Researchers have been using spectral observations to explore the atmospheric composition of different bodies in our solar system. In addition, they need to determine the processes that generate phosphine in abiotic environments.
The presence of phosphine in gas giant atmospheres and now on a brown dwarf raises intriguing questions about its chemical pathways. This finding means that phosphine can be produced chemically by non-biological processes under certain conditions. This discovery has the potential to alter the way scientists look for biosignatures in space.
Additionally, knowing how these processes work is important when thinking about other possible habitats for life beyond our planet. Phosphine’s recent alleged detection in other, quite diverse environments calls for more open-minded thinking by researchers. This might provide a fresh perspective when looking for evidence of life elsewhere in the universe.