Effect of k₂ uncertainty on the ability to constrain the interior for Earth (a) and Neptune (b) analogs. Each panel shows the marginal distributions for each interior layer with increasing amounts of k₂ uncertainty. An uncertainty of 5 in mass, 3 in radius, and 2% in T_eq has been assumed for both planets in all cases.^(*) Instead of Neptune’s equilibrium temperature of 51 K, a value of 100 K was used to be in line with the parameter range of the training data.