Titan

Methane lakes under a thick orange sky

Titan is Saturn's biggest moon and the only moon wrapped in a thick orange haze. Underneath are rivers, lakes and seas — not of water, but of liquid gas (methane)! It rains methane there. The air on Titan is so thick and gravity so weak that with wings strapped on you could fly!

Titan (radius 2,575 km) is Saturn's largest moon and the second largest in the Solar System, orbiting every 16 days. It is the only moon with a dense atmosphere: pressure 1.5 times Earth's, made of 95% nitrogen plus methane. Methane plays the role water plays on Earth: clouds, rain, rivers and polar seas such as Kraken Mare (400,000 km²). The surface is −179 °C and ice is as hard as rock; beneath it there is probably an ocean of liquid water. In 2005 ESA's Huygens probe landed on Titan — the first landing in the outer Solar System. NASA's Dragonfly (launching 2028) is a flying drone that will arrive in 2034 to study the chemistry of life.

Fun facts

• Titan is the only moon with an atmosphere; its sky is orange and the Sun looks dim.
• Raindrops on Titan are twice as big and fall slowly, like snow.
• Titan is bigger than Mercury, but half of it is ice — so it's light.