Titan's atmosphere changes with seasons Madrid - Agencies Saturn's moon Titan shows seasonal changes in its 30-year solar orbit, driven by the same forces that create Earth's seasons, a European researcher revealed. The main cause of changes is solar radiation, which acts as the dominant energy source for Titan's atmosphere, mirroring what happens on Earth, said Athena Coustenis from the Paris-Meudon Observatory in France. "As with Earth, conditions on Titan change with its seasons. We can see differences in atmospheric temperatures, chemical composition and circulation patterns, especially at the poles," Coustenis said. "This is all very surprising because we didn't expect to find any such rapid changes, especially in the deeper layers of the atmosphere." Titan's rotational axis is inclined at around 27 degrees, similar to Earth, meaning seasons are caused by sunlight reaching different areas with varying intensity due to the tilt in the same manner for both worlds, Coustenis said. "It's amazing to think that the Sun still dominates over other energy sources even as far out as Titan, over 1.5 billion kilometers from us," she said. Coustenis presented the results at the European Planetary Science Congress in Madrid Friday.