ɪt wʌz haɪpˈɑːθəsˌaɪzd ɪn nˈaɪntiːnhˈʌndɹɪd fˈɪfti sˈɛvən baɪ jˈʊɹɹi ænd bɹˈuːɚ ðæt sˌiːˈoʊ plˈʌs, sˌiːˈoʊ ænd ˈoʊ ˈaɪɑːnz pɹədˈuːst baɪ ðɪ ˌʊltɹɐvˈaɪəlɪt ɹˌeɪdɪˈeɪʃən fɹʌmðə sˈʌn wɜː ðə kˈɔːz ʌvðə ɡlˈoʊ.
It was hypothesized in 1957 by Urey and Brewer that CO+, CO and O ions produced by the ultraviolet radiation from the Sun were the cause of the glow.