atom. When two methyl radicals recombine, the result is ethane:

: CH₄ -> CH₃o + oH
: CH₃o + oCH₃ -> C₂H₆

In Earth's atmosphere, hydroxyl radicals convert ethane to methanol vapor with a half-life of around three months.

It is suspected that ethane produced in this fashion on Titan rains back onto the moon's surface, and over time has accumulated into