Astronomers studying LHS 1903 have discovered a planetary system that defies traditional formation models. Instead of a distant gas giant, the outermost planet is rocky — contradicting the standard view that solid worlds form close to their stars while gaseous giants form farther out.

Researchers propose an inside-out, sequential formation process, where early atmospheric gases were depleted before the final planet formed. The finding forces a reassessment of how and when planets assemble — and highlights the growing diversity of planetary systems across the galaxy.

This episode includes AI-generated content.