Information about planets in our Solar System
Age on another planet is checked
There are 8 known planets in our solar system and at least 5 dwarf planets (Ceres, Pluto, Makemake, Haumea and Eris). Ceres orbits sun in the asteroid belt between Mars and Jupiter, other dwarf planets much further away behind Neptune's orbit.
The closer the planet is to sun, the shorter time it takes to orbit it. One round around the sun is always one year on the planet.