Research Spotlight: Iron oxide observed in Earth's airglow



[1] The Earth's night airglow, a weak emission of light caused by chemical reactions in the planet's atmosphere, has been studied for more than a century. Because iron is common in meteorites that deposit debris in Earth's atmosphere, it was expected that iron oxide (FeO) would be found in the airglow, but it had not been detected until now. Evans et al. report observations made using the Optical Spectrograph and Infrared Imager System (OSIRIS) on the Odin spacecraft that show orange bands at about 600 nanometers in the night airglow spectrum. Comparison with published laboratory measurements of FeO emission spectra indicate that the observed orange bands in the airglow are probably due to FeO. The researchers suggest that the orange-band FeO emission is probably produced through interactions of iron with ozone in the atmosphere. (Geophysical Research Letters, doi:10.1029/2010GL045310, 2010)