This inside-out planetary system has astronomers scratching their heads

The star LHS 1903 features an unusual planetary arrangement that challenges conventional formation models, with two rocky planets sandwiching two gaseous ones in a rocky-gaseous-gaseous-rocky configuration from the star outward. This "inside-out" system defies expectations that rocky planets form close to their star while gaseous planets develop further away. Scientists believe the strange lineup resulted from violent planetary migration early in the system's history, where gravitational forces caused planets to move inward and potentially stripped atmospheres from outer worlds.