At about 55 hours and 40 minutes into the flight, and 13 hours before entering lunar orbit, the crew of Apollo8 became the first humans to enter the gravitational sphere of influence of another celestial body.
æɾ ɐbˌaʊt fˈɪfti fˈaɪv ˈaʊɚz ænd fˈoːɹɾi mˈɪnɪts ˌɪntʊ ðə flˈaɪt, ænd θˈɜːtiːn ˈaʊɚz bᵻfˌoːɹ ˈɛntɚɹɪŋ lˈuːnɚɹ ˈɔːɹbɪt, ðə kɹˈuː ʌv ɐpˈɑːloʊ ˈeɪt bɪkˌeɪm ðə fˈɜːst hjˈuːmənz tʊ ˈɛntɚ ðə ɡɹˌævɪtˈeɪʃənəl sfˈɪɹ ʌv ˈɪnfluːəns ʌv ɐnˈʌðɚ səlˈɛstjəl bˈɑːdi.