Mysterious Massive Planet Baffles Astronomers with Longest Orbit

Astronomers have discovered a Neptune-sized planet, TOI-1853b, with a density higher than steel, suggesting it may have formed through giant planetary collisions. The planet's mass is almost twice that of any other similar-sized planet known, and its high density indicates a larger fraction of rock than expected. The study connects theories of planet formation in the solar system to the formation of exoplanets, providing new insights into the prevalence of giant impacts in planetary systems throughout the galaxy. Further observations will be conducted to examine the planet's residual atmosphere and composition.