Our Solar System to Scale


Learning about space is great but sometimes there are misconceptions we develop as a society. In this activity and lesson the goal is to address misconceptions about size and distance in our solar system. Are the planets evenly spaced out? Are the planets relatively the same size? Students will learn about the actual distances between planets and their differences in size through tangible, hands-on examples. This is also an excellent conversation starter about the nature of science and science education; how is it that these misconceptions develop over time?

Check our video on this activity

Background information

The Sun is a yellow dwarf star. A medium sized star, very average, boring and middle-aged in comparison to other stars. The Sun’s atmosphere, called corona, is hotter than its surface.  The diameter of the Sun is about 100 times the diameter of the Earth i.e. you could fit about 100 Earths side-by-side across the face of the Sun.

The Sun is at the centre of our solar system and the planets orbit around it. From the Sun the planets are in order Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Jupiter’s diameter is roughly 11 times that of Earth’s and the Sun’s diameter is 10 times that of Jupiter. To make this a bit more visual, imagine the Earth as a cherry tomato at this size Jupiter would be about the size of a watermelon and the Sun would be the size of a playground’s merry-go-round!

On Earth we are roughly 150 million km away from the Sun and so it takes light from the Sun 499 seconds to get to Earth (just over 8 minutes). This distance is called an Astronomical Unit and is used when talking about vast distances in space. Using the paper activity it shows a more accurate picture of distances is our solar system. Another way to see these differences is in time for light to travel starting with Earth being 8 light minutes away from the Sun, going two planets further to Jupiter will take 36 more minutes, so it is around 44 light minutes from the Sun, and a further two planets away to Uranus is going to take another 2 hours, so Uranus is over 2.5 light hours away from the Sun! This is showing us that as we go outwards from the Sun the planets not only get further from the Sun, but the distance between the planets gets larger.

A common representation of the planets in the Solar System

A side-by-side comparison shows what is a stereotypical view of the solar system against a more accurate portrayal of the vast distances. By looking at images like these we can understand why the misconception exists.

A more accurate representation of the distances between planets in the Solar System