A positive corona discharge fed by a N 2 :CH 4 mixture (98:2) at atmospheric pressure and ambient temperature has been studied as a laboratory mimic of the chemical processes occurring in the atmosphere of Titan, Saturn's largest moon. In-situ measurements of UV and IR transmission spectra within the discharge have shown that the main chemical product is C 2 H 2, produced by dissociation of CH 4 , with small but significant traces of ethane and HCN, all species that have been detected in

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... atmosphere. A small amount (0.2 %) CH 4 was decomposed after 12 minutes of treatment requiring an average energy of 2.7 kWh/g. After 14 minutes the discharge was terminated due to the formation of a solid yellow deposit on the central wire electrode. Such a deposit is similar to that observed in other discharges and is believed to be an analogue of the aerosol and dust observed in Titan's atmosphere and is composed of chemcial species commonly knonw as 'tholins'. We have also explored the electrical properties of the discharge. The admixture of methane into nitrogen caused an increase in onset voltage of the discharge and consequently led to a reduction in the measured discharge current.