High-resolution FUV spectroscopy of the terrestrial day airglow with the far ultraviolet spectroscopic explorer

During orbital verification the Far Ultraviolet Spectroscopic Explorer obta ined spectra of the terrestrial day airglow between 905 and 1184 Angstrom f rom an altitude of 766 km. The spectrographs have three apertures chat call simultaneously record the atmospheric emissions with limiting instrumental spectral resolutions of approximately 0.4, 0.05, and 0.03 Angstrom. Seven orbits were obtained of observations of the sunlit Earth and disclose a wea lth of emissions resulting from the electron impact excitation of N-2 in ad dition to emissions of O I, N I, and N II produced by both photoelectron im pact and by photodestructive excitation and ionization of thermospheric O a nd N-2 by extreme ultraviolet solar radiation. The argon resonance transiti ons are unambiguously identified as are previously unreported transitions b etween highly excited energy levels of O+ These spectra have the highest sp ectral resolution and sensitivity in this spectral range to date and will p rovide valuable input to the interpretation of lower resolution spectra fro m current and future Earth remote sensing missions.