- The theory that is most accepted by scientists is that Saturn is a huge ball of gases with no solid surface like Earth has. The core of Saturn is thought to be solid, composed of iron and other rocky materials. A dense outer core that most likely is ammonia, methane and water surrounds the core, with a compressed layer of liquid hydrogen around that. Another layer that is made of helium and hydrogen is almost like syrup and is above the compressed hydrogen layer. Near the planet's surface this becomes gaseous in nature, with the atmosphere being lighter than the surface but mostly still hydrogen and helium. This mixture means the temperature of Saturn is colder near the top of the atmosphere than near the surface--much colder.
- Saturn is much farther from the sun than Earth is. It travels around the star in an oval, or elliptical, orbit that carries it as close as 840.5 million miles and as far as 942 million miles. In comparison, the Earth is an average of 93 million miles from the sun. Saturn's distance, which is almost 10 times farther than Earth, plays a huge factor in Saturn's temperature.
- Saturn's distance from the sun means that it takes much longer to complete one revolution around it. While Earth needs 365 days to orbit the sun one time, Saturn takes 10,759 days, or more than 29 years. A day on Saturn is much shorter than one on Earth, however. It takes Earth 24 hours to rotate once on its imaginary axis; Saturn needs only 10 hours and 39 minutes to do it. This means that Saturn's temperature is most likely uniform throughout the cloud tops.
- All of this means that Saturn is a frozen planet. The tops of the gaseous clouds average minus 285 degrees Fahrenheit. The temperatures below this hydrogen and helium gas layer are considerably warmer than those at the top, with estimates as warm as minus 20 degrees near the surface. The helium gradually sinking through the hydrogen is thought to create the chemical reactions that make this possible.
- Saturn actually experiences seasons since it is tilted 27 degrees from a perpendicular position on its axis. This tilt means that the northern and southern hemispheres receive different amounts of sunlight and heat as Saturn orbits the sun, creating seasons just like Earth's tilt on its axis does. But the seasons on Saturn each last over 7 years since it takes so long to complete one orbit.
