Phosphine in Jupiter's atmosphere: the evidence from high-altitude observations at 5 micrometers.

The presence of PH3 in Jupiter's atmosphere is confirmed with new spectroscopic observations at 5 m recorded from the Kuiper Airborne Observatory. The mixing ratio [P]/[H2] estimated from these observations is consistent with the solar value of6 x 10- . The availability of abundant phosphorus throughout the spectroscopically accessible regions of Jupiter's atmosphere has important implications for the production of chromophores in the cloud layers and the observed low abundance of water vapor. Subject headings: planets: abundances - planets: Jupiter - planets: spectra