Visual Tour of the Solar System

Pluto, the Roman ruler of the underworld. On August 24, 2006, the International Astronomical Union (IAU) formally downgraded Pluto from an official planet to a dwarf planet. Its orbit is so eccentric it brings Pluto inside the orbital path of Neptune. It orbits the Sun once in 247.7 Earth years at an average distance of 5.91 billion km. Its rotation is reverse that of other planets. Pluto is about 2,360 km (1,475 mi) in diameter. Pluto has 1 satellite, Charon, about 1200km in diameter.

Clearest view yet of Pluto and its moon, Charon, by Hubble Space Telescope.

Our tour would not be complete if we didn't also check out some of the smaller bodies in our solar system.

We now know that comets are dirty-ice leftovers from the formation of our solar system around 4.6 billion years ago. They are among the least-changed objects in our solar system and, as such, may yield important clues about the formation of our solar system. We can predict the orbits of many of them, but not all.

From NASA's Spitzer Space Telescope an image of the comet Encke.

Asteroids are rocky fragments also left over from the formation of the solar system. Most of these fragments of ancient space rubble - sometimes referred to by scientists as minor planets - can be found orbiting the Sun in a belt between Mars and Jupiter.

A mosaic of Eros' southern hemisphere, taken by NEAR Shoemaker.

That ends our brief visual tour of the solar system. If you want more, visit our complete Solar System Tour.