Core Earth Material ‘Silicate’ Detected for the First Time, Unlocking Secrets of the Solar System’s Birth

A Korean research team has identified, using observational evidence, a key mechanism that explains the origin of high-temperature minerals in the early Solar System. For the first time in the world, they have directly observed silicates forming as a star is born; silicates are core materials that make up about 90% of Earth’s crust. This breakthrough was made possible after the team secured highly competitive observing time on the James Webb Space Telescope (JWST), which enables extremely precise measurements.
The Ministry of Science and ICT announced on the 22nd that a team led by Professor Jeong-Eun Lee at SNU has, for the first time globally, observed and demonstrated the crystallization process of silicates during star formation. The study was carried out with support from the Basic Research Program of the Ministry of Science and ICT (MSIT), and the results were published on the 21st (local time) in Nature, one of the world’s most prestigious scientific journals. According to the team, silicates are key components of terrestrial planets and comets, accounting for about 90% of the material that makes up Earth’s crust. In particular, crystalline silicates are known to form only in high-temperature environments above 600°C. Yet crystalline silicates have been found in comets located in the extremely cold outer regions of the Solar System, raising a long-standing question of how materials formed in hot regions could have been transported to the Solar System’s outskirts.
Professor Jeong-Eun Lee has spent more than 20 years studying how stars are born and had predicted that explosive mass accretion onto protostars would fundamentally alter the chemical state of the material that later forms comets. However, at the time, no telescope had the sensitivity and resolution needed to observe such changes directly and in detail.
This situation changed when the National Aeronautics and Space Administration (NASA) successfully launched the James Webb Space Telescope (JWST), which has the capabilities required to test these theoretical predictions. With JWST, an environment finally emerged in which the long-envisioned research could actually be carried out. In particular, Professor Lee’s team secured JWST observing time as the only group in Korea to do so. They explained that this was possible thanks to their previous research data, which enabled them to win observing time in a highly competitive selection process.
The team focused on the protostar EC 53, located in the Serpens Nebula. EC 53 is an object whose brightness varies with a period of about 18 months, allowing its outburst and quiescent phases to be clearly distinguished. The researchers observed EC 53 both during its quiescent phase and during an outburst. They found that the spectral signature of crystalline minerals appeared only in the outburst phase. This confirmed that silicate crystallization is actually occurring in the hot inner region of the disk close to the protostar. The team also showed that crystalline silicates formed in the inner disk can be transported to the cold outer regions by a disk wind.
This study provides the world’s first explanation of both the formation and transport mechanisms of crystalline silicates. It offers an important benchmark for understanding how mineral components in comets and planets form and are distributed, and is expected to greatly improve the reliability of Solar System formation models. Because the mechanism can also be applied to planetary system formation around stars other than the Sun, the results are anticipated to serve as a key reference for future time-series observations using JWST. The team plans to discover more protostars that undergo explosive brightening through time-series observations with various ground-based telescopes and infrared space telescopes, and then conduct follow-up observations of these objects with JWST.
Professor Lee stated, "I believe this achievement is a case where experience accumulated over a long period has led to a scientific discovery," adding, "We plan to carry out follow-up observations to test how universal the processes of silicate crystallization and material transport are, and how they depend on the evolutionary stage."
jiany@fnnews.com Yeon Ji-an Reporter