We present the first observations of propane ( C _ { 3 } H _ { 8 } ) on Titan that unambiguously resolve propane features from other numerous stratospheric emissions .
This is accomplished using a R = \lambda / \delta \lambda \approx 10 ^ { 5 } 
spectrometer ( TEXES ) to observe propane ’ s \nu _ { 26 } rotation-vibration band near 748 cm ^ { -1 } .
We find a best-fit fractional abundance of propane in Titan ’ s stratosphere of ( 6.2 \pm 1.2 ) \times 10 ^ { -7 } in the altitude range to which we are sensitive ( 90-250 km or 13-0.24 mbar ) .