Year 7 · Science · Space · Lesson 1
The solar system and gravity
The Sun and eight planets, stars, moons, galaxies and light years, and how gravity holds planets in orbit and changes weight on the Moon.
17-minute video lesson
Teaching, worked examples and 20 practice questions solved step by step.
Watch free for a monthWhat your child will learn
- Order the planets
- Define key space words
- Explain how gravity keeps planets in orbit
- Calculate weight on Earth and the Moon
The method
- Mass.
- Distance.
- Mass constant.
- W = m x g.
Key words: solar system, planet, orbit, gravity, galaxy, light year.
Worked examples
The first three practice questions from the lesson, with every step.
Question 1
What is at the centre of our solar system?
- Step 1: Star
Answer: the Sun
Question 2
How many planets are in our solar system?
- Step 1: Count
Answer: eight
Question 3
Which planet is closest to the Sun?
- Step 1: M...
Answer: Mercury