FIG. 8.

Shown here are spectra for Case B. Haze and gas absorption features are labeled with the symbols indicated. (a) At short wavelengths in direct imaging, haze absorption decreases the planet's brightness; scattering brightens the planet at longer wavelengths. (b) Thermal emission from the hot stratosphere of the thickest haze planet (CH₄/CO₂ = 0.21) fills in absorption bands near 8 and 16 μm. (c) The y axis shows the effective transit height above the planet's surface that light is able to penetrate, and absorption features are inverted compared to (a) and (b) due to an increase in the effective planet radius during transit resulting from an increase in absorption at these wavelengths. The bottom section shows the approximate color of the hazy sky and planet. Sky colors are computed using the diffuse radiation spectrum at the ground. “Effective tangent height” refers to the minimum altitude above the planet's surface that light is able to penetrate on transit transmission paths.