The inner planets are the four planets closest to the Sun: Mercury, Venus, the Earth and Mars.
They are terrestrial or rocky planets. The crust and mantle are made of rock. The core is metallic.
The Earth is the only planet that has life on it.
In 2004, the robots Spirit and Opportunity landed on Mars.
Inner planets Mercury Venus Earth Mars Interesting characteristics The smallest and closest to the Sun Rotates in opposite direction The only planet with life Very thin atmosphere Average surface temperature -180ºC to 430ºC 465ºC -89ºC to 58ºC -82ºC to 0ºC
Jupiter, Saturn, Uranus and Neptune are the four outer planets. They are called gas giants .
Outer planets Jupiter Saturn Uranus Neptune Interesting characteristics Largest planet, most satellites System of rings Rotational axis almost horizontal Greatest distance from the Sun Average surface temperature -150ºC -170ºC -200ºC -210ºC