The Sun, planets and asteroids

Question 1

Sun

Answer 1

The only star in our solar system

Question 2

Solar system

Answer 2

The Sun and all the objects that travel around it

Question 3

Planet

Answer 3

A large object that revolves around the Sun

Question 4

Star

Answer 4

A huge ball of burning gas in space

Question 5

Orbit

Answer 5

The path of one object in space around another, such as the path of the Earth around the Sun

Question 6

Asteroid

Answer 6

Chunks of rock that travel around the Sun

Question 7

Moon

Answer 7

A solid rocky body that travels round a plane

Question 8

Atmosphere

Answer 8

The layer of gas around a planet or other object in space

Question 9

Model

Answer 9

A model is a simplified version of something that helps us understand the real thing better

Question 10

The Sun is at the center of our solar system

Answer 10

• Sun = star = only star in our solar system
• All stars = balls of very hot gas = give out heat and light
• The other stars are much further away = we do not feel their heat, or benefit from their light

Question 11

The planets and the asteroid belt

Answer 11

• Planets = different from stars = not made of hot gas = cannot give out their own heat and light.
• Eight planets = Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune
• All planets travel around the Sun in a path = orbit
• Every planet has its own orbit around the Sun. The shape of each orbit is a bit like a flattened circle.
• We call a shape like this an ellipse.
• Asteroids are chunks of rock that travel around the Sun.
• There are hundreds of thousands of asteroids.
• The largest asteroid, Ceres, has a diameter of 1 000 km
• Most asteroids travel around the Sun between the orbits of Mars and Jupiter.
• This part of the solar system is known as the asteroid belt

Question 12

Each planet is different

Answer 12

The planets are not all the same. Each planet has its own features. Planets are all different in size, move in different orbits and are different distances from the Sun. They also have different compositions: some are rocky like the Earth and others are gas planets. The four inner planets are solid rocky bodies; the four outer planets are gas giants – huge balls of gas. They have different numbers of moons.

Question 13

The planets and asteroids take different amounts of time to revolve around the Sun

Answer 13

The Earth takes 365 ¼ days to revolve around the Sun. We round this off to 365 days most years. Every fourth year we have an extra day to make up the missing quarter days. This longer year is called a leap year. We use Earth days and years to measure the time it takes the other planets and the asteroids to revolve around the Sun.