Nadir pointing spectra obtained between 30.51 and 31.00 August 2015. The vertical scale is main beam brightness temperature in K. The horizontal scale is Doppler velocity relative to the nucleus. Lines are seen in absorption against the nucleus background temperature at 209 K and are blueshifted by −0.8 km s⁻¹ because most of the gas flows toward MIRO/Rosetta. The position and expected relative intensities of the hyperfine components of the HO and NH₃ lines are shown. They are displaced by −0.8 km s⁻¹ , which is the mean gas bulk velocity as seen in other lines. Narrow spikes, which are instrument artifacts, appear regularly in the spectra of ammonia and two of the methanol lines.