Astronomers have discovered a planetary system that challenges existing planet formation theories. Using the European Space Agency's Cheops space telescope, researchers observed four planets orbiting a red dwarf star called LHS 1903, located about 117 light-years from Earth in the Lynx constellation.

The system's configuration is puzzling: two rocky planets orbit closest to the star, followed by two gaseous planets, with the outermost planet unexpectedly being rocky rather than gaseous as current theories predict. This arrangement contradicts the established paradigm that planets close to their host star should be small and rocky, while those at greater distances should be gas-rich.

The discovery suggests planets may form sequentially rather than simultaneously in a large disk of gas and dust. The fourth planet likely formed later in a gas-poor environment, or possibly lost its atmosphere through a catastrophic collision. This finding could reshape our understanding of planetary formation and habitability, as the fourth planet, with a mass 5.8 times that of Earth and temperatures around 60 degrees Celsius, sits in a potentially habitable zone.