Astronomers have uncovered a distant planetary system that flips a long-standing rule of planet formation on its head. Around the small red dwarf star LHS 1903, scientists expected to find rocky planets close in and gas giants farther out — the same pattern seen in our own Solar System and hundreds of others. And at first, that’s exactly what they saw. But new observations revealed a surprise: the outermost planet appears to be rocky, not gaseous.