Eight known planets and their moons, along with comets, asteroids, and other space objects orbit the Sun.. Astronomers think the solar system is more than 4 billion years old.Astronomers
Trang 1The Solar System
What is the solar system?
It is our Sun and everything that travels around it
Our solar system is elliptical in shape
That means it is shaped like an egg
The Sun is in the center of the solar system
Our solar system is always in motion
Eight known planets and their moons, along with comets, asteroids, and other space objects orbit the Sun
The Sun is the biggest object in our solar system
It contains more than 99% of the solar system's mass
Trang 2Astronomers think the solar system is more than 4 billion years old.
Astronomers are now finding new objects far, far from the Sun which they call dwarf planets
Pluto, which was once called a planet, is now called a dwarf planet
1 What is the solar system?
2 What shape is our solar system?
3 Where is the Sun located in the Solar system?
4 How many planets orbit the Sun?
5 How old is the solar system thought to be?
Trang 3The Planets and Dwarf Planets
A planet is a large space object which revolves around a star
It also reflects that star's light
Eight planets have been discovered in our solar system
Mercury, Venus, Earth, and Mars are the planets closest to the Sun
They are called the inner planets
The inner planets are made up mostly of rock
The outer planets are Jupiter, Saturn, Uranus, and Neptune
Jupiter, Saturn, Uranus, and Neptune are large balls of gases with rings around them All eight planets travel around the Sun in a different orbit
In its orbit, there are not many other objects like the planet
Dwarf planets are objects that are similar to planets except that they orbit the Sun in areas where there are many similar objects