Main characteristics of the Solar System

In the universe there are millions of galaxies. A galaxy is formed of a lot of celestial bodies, gasses, dust and other materials. A galaxy contains thousands of millions of stars. Stars are celestial bodies formed of very hot gasses. They emit energy in the form of light and heat. Stars are classified according by three characteristics: colour, luminosity and size.

Our Solar System is made up of all the celestial bodies that orbit the Sun. It is in the galaxy called the Milky Way.

The star that we call the Sun is at the centre of the Solar System. It is an enormous ball of gas. more than 1,400,00 Earths could fit inside of the Sun!

All of the other celestial bodies orbit around the sun. They do not orbit in a perfect circle; they orbit it in an elliptical shape.

The sun provides light and thermal energy. The Earth is at the perfect distance from the Sun to allow us to have life on it. It takes 365 days for the Earth to rotate around the Sun.

Eight planets, their satellites and other objects move around the sun. The eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Around some planets, there are satellites. The earth has one satellite: the Moon

Between the orbits of Mars and Jupiter are a group of rocks called the asteroid belt. Asteroids are fragments of rock or metal.

Asteroids are fragments of rock or metal. They are called meteorites if they hit a planet or as satellite and they form craters on the surface.

Small meteorites that disintegrate in our atmosphere are called shooting stars.

Many of the other planets in our Solar System also have moons. Both Jupiter and Saturn have more than 60 different moons; each moon is a different size and follows a different orbit around its planet.

Dwarf planets are smaller than planets. They orbit the Sun further away than Neptune. Pluto is the best well known.

Comets are made of rock and ice. Solar energy evaporates the ice which forms a tail.