... ESO . ... According to the first ever infrared analysis of the atmosphere of Neptune's moon Triton, summer is in full swing in its southern hemisphere. The European observing team used ESO's Very Large Telescope and discovered carbon monoxide and made the first ground-based detection of methane in Triton's thin atmosphere. ... Climate and atmospheric models of Triton have to be revisited now, now that we have found carbon monoxide and re-measured the methane, " says co-author Catherine de Bergh. ...