Ternary plot for Kepler-102e (K-102e) solid core compositions, assuming a core radius of R c = 1.5 R ⊕. Large points represent planet compositions consistent with our measured mass of the planet to within 1σ, while smaller points represent compositions within 2σ. The planet core composition that most closely matches our measured value of M e = 4.7 M ⊕ is one of 40% iron and 60% silicate rock—more dense than the best-fit composition for Kepler-102d.