---
title: "The Vast Scale of Space"
description: "Describe the scale of the universe in nested layers: Earth is one planet in our solar system, the Sun is one star among billions in the Milky Way galaxy, and the Milky Way is one galaxy among billions"
canonical: https://lightmysky.com/learn/science/the-vast-scale-of-space-mt_aulwq39aj8
source: https://lightmysky.com/learn/science/the-vast-scale-of-space-mt_aulwq39aj8.md
retrieved: 2026-10-19
---

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# The Vast Scale of Space

Describe the scale of the universe in nested layers: Earth is one planet in our solar system, the Sun is one star among billions in the Milky Way galaxy, and the Milky Way is one galaxy among billions in the universe

Subject: Science · Area: Space Exploration · Ages 9 to 11
Page: https://lightmysky.com/learn/science/the-vast-scale-of-space-mt_aulwq39aj8

## Ready when they can

- State that the Milky Way is our galaxy and it contains billions of stars
- Explain the hierarchy: planet → solar system → galaxy → universe
- Use a comparison to convey cosmic scale (e.g. if the Sun were a football, Earth would be a peppercorn 26 metres away)

## Lesson: The Vast Scale of Space

You know Earth is a planet, and it travels around the Sun with seven other planets. That whole family of planets and the Sun is called the solar system. Now let's zoom out even further.

The Sun is a star, just like the tiny sparkly dots you see in the night sky. But the Sun is not alone. It belongs to a huge group of stars called a galaxy, and our galaxy has a name: the Milky Way. It holds billions of stars.

*(drawing: Each step holds the one before it. Earth sits inside all four, out to the whole universe.)*

**Example.** Imagine shrinking the Sun down to the size of a football. On that same tiny scale, Earth would be a peppercorn sitting about 26 metres away. That huge gap is mostly empty space, and it is just our tiny corner of one galaxy.

**Tip.** The Milky Way is huge, but it is only one galaxy. Scientists have counted billions of other galaxies out there, each packed with its own billions of stars.

**Recap.** Planet, solar system, galaxy, universe: each one holds many of the one before it, all the way out to a universe of billions of galaxies.

## Practice

8 questions on this page, each with its working shown.

## Needs first

- [The Eight Planets](https://lightmysky.com/learn/science/the-eight-planets-mt_AVk2EmSULC)
- [The Sun is a star](https://lightmysky.com/learn/science/the-sun-is-a-star-mt_u3Y3Tb-G_n)

## Opens up

- [Scale of the Solar System](https://lightmysky.com/learn/science/scale-of-the-solar-system-mt_TlGhXAqC4p)
- [Finding Exoplanets](https://lightmysky.com/learn/science/finding-exoplanets-mt_UjuriPLVgT)