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==> In this proposal, more time is being requested for BBEZARD.NEP_2
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We first propose to search for methyl radical (CH3) on Neptune using the
grating mode of the SWS. This observation is a follow-up of the accepted
proposal NEP_2 in which we originally proposed to search for various
hydrocarbons on Neptune. The CH3 observations had to be removed to fit within
the allocated time. We also propose to extend this search to Saturn using the
F-P mode of the SWS. Photochemistry of methane in the atmospheres of the
giant planets leads to the formation of various hydrocarbons. Methyl radical
is supposedly the key pathway to the formation of ethane, the most abundant
photochemically-produced molecule. Detecting this compound would provide an
important test for some chemical schemes proposed in photochemical models
and would help determining some poorly constrained atmospheric parameters
such as the eddy mixing profile.