TOI-1685 b’s measured dayside NRS2 brightness temperature ratio (﹩{ \mathcal R }﹩) in the context of other rocky exoplanets as a function of irradiation temperature (the substellar temperature of a blackbody). Point size is proportional to planet size. TOI-1685 b follows the trend of blackbody-like emission for ∼1000–2000 K planets, suggesting no significant atmospheres and dark surfaces. The most compelling evidence for atmospheres has come from planets hot enough to vaporize rock. Data are taken from, in order of increasing irradiation temperature: TRAPPIST-1 c (S. Zieba et al. 2023), TRAPPIST-1 b (averaged from MIRI F1280W and F1500W, E. Ducrot et al. 2025), LTT 1445 A b (P. Wachiraphan et al. 2025), GJ 1132 b (Q. Xue et al. 2024), LHS 1478 b (P. August et al. 2025), TOI-1468 b (E. Valdés et al. 2025), GJ 486 b (M. Weiner Mansfield et al. 2024), LHS 3844 b (L. Kreidberg et al. 2019), GJ 1252 b (I. J. M. Crossfield et al. 2022), GJ 367 b (M. Zhang et al. 2024), TOI-431 b (C. Monaghan et al. 2025), 55 Cnc e (R. Hu et al. 2024), and K2-141 b (S. Zieba et al. 2022).