Astronomy (and more in general science) education must confront a wide array of misconceptions. For example, contrary to what schoolbook illustrations or artistic impressions might suggest, the distances between celestial bodies are unimaginably vast, far beyond what the human mind can easily understand. The Solar System (and space more in general) is essentially empty. Similarly, the tiny size of our beloved planet Earth—when compared to larger planets or stars—also challenges our perception.
To truly grasp the scale of distances and sizes in the Solar System (and beyond), it is extremely useful to compare them to familiar physical places that we, as humans, can experience directly—places we can walk through, measure, and relate to. Knowing that the Earth is one astronomical unit from the Sun, or that its diameter is about 1% of the Sun’s diameter, is not as impactful as imagining that if the Sun were the size of a car, the Earth would be located at a distance of 400m and would be no bigger than a cherry tomato.

In this presentation, we showcase an application of this conceptual approach to illustrating astronomical distances and sizes, as developed for the large-scale exhibition Time Machines (https://macchinedeltempo.inaf.it/), created by INAF, the Italian National Institute for Astrophysics, in 2023 and put on display in two different locations in Italy in 2024 and 2025.

In the section dedicated to the Solar System, the idea is to “play” with visitors by imagining a scaled-down version of our planetary system overlaid on their own city. The Sun is represented by a large inflatable sphere with a diameter of about 3.5 meters (the dimension of a car) placed in the center of the exhibition. Thanks to a large city map displayed in the room, visitors can locate by themselves the scaled-down positions and sizes of the planets, physically experiencing how far they would have to walk—identifying the square, the street, or the monument where they could find each planet.

Using the same “human-scale” approach to represent astronomical dimensions and distances, we will also present Space City Tour (currently under development with the collaboration of the companies Explora and ArkadIA), a web-app that will enable users to explore the Solar System through an augmented reality walk through their own city. Just using their smartphone, users will be able to view 3D models of the Sun and planets emerging in specific urban locations, recreated in augmented reality with realistic scale and spacing.

Keywords: Solar system, maps, informal education.