(Main) An illustration of a protoplanetary disk; (inset) an artist's rendition of the James Webb Space Telescope.
(Image credit: ESA/NASA, the AVO project and Paolo Padovani)
Using the James Webb Space Telescope (JWST), astronomers have studied 72 young, sun-like stars. As a result, they found that forming planets is a real race against time.This is because the material that serves as the building blocks for planets is constantly escaping the swirling platters of gas and dust, or protoplanetary disks, that wrap around infant stars. Some types of planets may find their formation window closing sooner than others.The team's research represents the most in-depth investigation yet into how matter escapes these protoplanetary disks and how this escape gives rise to different stages of planet formation around sun-like stars. All in all, the study helps paint a better picture of how and why our solar system took the shape it did around the infant sun around 4.6 billion years ago."Gas giants like Jupiter must assemble their massive atmospheres while the disk is still substantial enough to supply them, before winds and jets carry that raw material away into space," team leader Naman Bajaj from the University of Arizona said in a statement.An ill wind blows around infant starsThe team conducted its research using data collected by the JWST’s Mid-Infrared Instrument (MIRI). The scientists tracked matter loss by following the movements of molecular hydrogen, one of the most common molecules in protoplanetary disks. Each of the stars involved in the investigation represented a different stage in the early life of a star system. That meant putting these snapshots together allowed the researchers to create a "movie" detailing the early life of a planetary system.One of the most important findings of this approach is the mechanisms for material loss from protoplanetary disks seem to evolve and switch dominance as an infant star ages.This is important because gas giants like Jupiter and Saturn have vast atmospheres. They thus require more raw material to form than smaller rocky worlds like Earth do. Understanding matter loss allows scientists to determine at what stages of protoplanetary disk evolution gas giants can form."What is exciting about this study is that we can now see, across a large sample of young systems, how the mechanisms that remove gas from planet-forming disks change with time," team member Uma Gorti from the SETI Institute said in the statement. "Disk dispersal sets a fundamental clock for planet formation: once the gas is gone, the opportunity to build gas-rich planets is essentially over."
