Acetonitrile in Titan’s Atmosphere from ALMA Radio Telescope Observation

Clifford Hall, Room 210

Titan is the largest satellite of Saturn and the only natural satellite that has significant atmosphere in the Solar System. Titan’s atmosphere was first suspected by Joseph Comas I Solá in 1903 and confirmed by Gerard Kuiper in 1944 with detection of methane. The Cassini-Huygens mission arrived in Saturn’s orbit in 2004 has primary mission to study about Saturnian system (Saturn and satellite). The prime Cassini-Huygens mission (2004–2008) has taught us a lot about the chemical composition of the Titan’s atmosphere. The data we have acquired regarding the vertical profile, latitude distribution, and seasonal changes of various photochemical compounds has significantly increased our understanding of Titan’s atmosphere. Extended monitoring of the seasonal variations of composition is a vital component to understand Titan’s meteorology. This had also been a major motivation for extending Cassini operations up to Saturn’s northern Summer solstice in 2017. ALMA (Atacama Large Millimeter/submillimeter Array) is an interferometer radio telescope at 5000 m altitude in Atacama, Chile, consisting of 66 antenna radio telescopes observing at millimeter and submillimeter wavelengths. Abundances of acetonitrile (CH3CN) has been detected in Titan’s atmosphere using ALMA data. The levels of CH3CN were found increase from surface up to an altitude of 800 km. The ALMA data of CH3CN are lower than Marten et al. (2002) showing seasonal variation in Titan’s atmosphere.