Mass-radius distribution of all confirmed planets with R_p < 4 R_⊕ from the NASA Exoplanet Archive with mass and radius determination better than 20%. The red dot represents TOI-5398 c, the beige dot ΤΌΙ-2000 b, the green dot TOI-1130 c, and the violet dots are respectively WASP-47 d and e. We include the Solar System planets Earth. Venus, Uranus, and Neptune. We add theoretical mass–radius curves from Zeng et al. (2019): solid brown indicates an Earth-like rocky core (32.5% Fe and 67.5% MgSi03), beige a 100% water world at 1000 K, and dotted beige a 1% hydrogen envelope and 99% Earth-like rocky core at the same temperature. Grey dashed curves represent densities ρ = 0.5, 1, and 5 g cm⁻³, respectively.