Alkanes form a small portion of the atmospheres of the outer gas planets such as Jupiter (0.1% methane, 2 ppm ethane), Saturn (0.2% methane, 5 ppm ethane), Uranus (1.99% methane, 2.5 ppm ethane) and Neptune (1.5% methane, 1.5 ppm ethane).
ˈælkeɪnz fˈɔːɹm ɐ smˈɔːl pˈoːɹʃən ʌvðɪ ˈætməsfˌɪɹz ʌvðɪ ˈaʊɾɚ ɡˈæs plˈænɪts sˈʌtʃ ɐz dʒˈuːpɪɾɚ zˈiəɹoʊ.wˈʌn pɚsˈɛnt mˈɛθeɪn, tˈuː pˌiːpˌiːˈɛm ˈɛθeɪn, sˈæɾɜːn zˈiəɹoʊ.tˈuː pɚsˈɛnt mˈɛθeɪn, fˈaɪv pˌiːpˌiːˈɛm ˈɛθeɪn, jˈʊɹɹænəs wˈʌn.nˈaɪnti nˈaɪn pɚsˈɛnt mˈɛθeɪn, tˈuː.fˈaɪv pˌiːpˌiːˈɛm ˈɛθeɪn ænd nˈɛptuːn wˈʌn.fˈaɪv pɚsˈɛnt mˈɛθeɪn, wˈʌn.fˈaɪv pˌiːpˌiːˈɛm ˈɛθeɪn.