Scientists have painted the most detailed portrait yet of the planetary system orbiting Barnard’s Star—the sun’s closest neighbor after Alpha Centauri, just under six light-years from Earth.

Discovered in 2025, the four planets orbiting Barnard’s Star are all smaller than Earth and Venus but larger than Mars—a type of planet not found anywhere in our own solar system.

By analyzing the chemical makeup of the star, the researchers from the University of Cambridge found that its planets are rich in a rare mineral called periclase, which on Earth is found only hundreds of kilometers (hundreds of miles) below the surface.