An international team of scientists from Trinity College Dublin, using the James Webb Space Telescope (JWST), has made groundbreaking observations in the YSES-1 planetary system, located nearly 17 million light-years from Earth. Their research, published in the prestigious journal Nature, provided a glimpse into the atmospheres of two giant exoplanets — YSES-1b and YSES-1c. 

The planet YSES-1c proved to be particularly interesting. Researchers recorded a signal in its atmosphere indicating the presence of clouds composed of silicates — substances resembling the components of Earth’s sand. As the authors of the study emphasize, this is the strongest silicate light absorption feature observed in an exoplanet to date. 

The young age of the planet (and the entire system) allows it to still maintain a higher temperature from its formation, which in turn promotes the formation and maintenance of clouds at high altitudes. The team not only identified the chemical composition of these clouds but also determined the sizes and shapes of particles that make them up. 

The second planet, YSES-1b, also surprised astronomers: although the YSES-1 system is already too old to contain a protoplanetary disk, a ring of hot, dusty material has been discovered around this planet, which may be the site of the formation of new moons, similar to those orbiting Jupiter. 

This makes YSES-1b only the fourth known planet with its own disk, and the only one with a disk that has survived for so long. Scientists are wondering how it is possible that this disk has not disappeared despite the passage of millions of years. 

Thanks to JWST, astronomers can compare young planetary systems with our own Solar System and better understand how Jupiter-like planets form, how long does it take, and what building materials play a key role in this process.