As we've explained, the scale of the solar system is mind-bogglingly extreme. Simply drawing a real diagram of it is wildly impractical.

But suppose we want to build an actual, physical model of it, despite this. What would it take?

Existing Models

A few people have actually had a go at making solar system models, and you can travel to see the results.

The Sweden Solar SystemSweden Solar System
Home page of the Sweden Solar System, the world’s largest model of our planetary system. (Project home page)
https://www.swedensolarsystem.se/en/ is the world's largest permanent scale model of the Solar System. The Sun is represented by the Ericsson Globe in Stockholm, the largest hemispherical building in the world. The inner planets can also be found in Stockholm but the outer planets are situated northward in other cities along the Baltic Sea. The model scale is 1:20 million.

Another large-scale model is the Solar System DriveSolar System Drive
A page about the Solar System Drive, the world’s largest Virtual Solar System Drive. (New South Wales Government)
https://www.nsw.gov.au/visiting-and-exploring-nsw/locations-and-attractions/worlds-largest-virtual-solar-system-drive, a drivable model in New South Wales, Australia. Here you can see three-dimensional planet models along the way as you shuttle from Pluto at the furthest reaches of the Solar System to the Sun, which is represented by the 37-metre Anglo-Australian Telescope dome at Siding Spring Observatory. The model scale is 1:38 million.

Aroostook County, in Northern Maine, is home to a 100-mile long scale model of the solar system, the Maine Solar System ModelMaine Solar System Model
A page about the Maine Solar System Model, the largest 3-D scale model of the solar system in the western hemisphere. (Project home page)
https://www.mainesolarsystem.com/, which extends for nearly 100 miles along U.S. Route 1, from the Sun at the University of Maine at Presque Isle to the dwarf planet Eris in Topsfield. The model is built at a scale of 1 mile equaling the distance from earth to sun — around 1:93 million.

A Country Park Model

So whatr if we want to make our own model? This would be a fascinating and beautiful project — but also extremely difficult in practice. Still, even thinking about it can help us to understand the crazy scale of our solar system.

So let's see what it would take to build a scale model of the solar system. We'll choose a scale of one to ten billion, because this is big enough to make the planets visible, but small enough to have a hope of fitting it in to a reasonable space.

For a location, let's choose Durlston Country ParkDurlston Country Park and National Nature Reserve
A page about Durlston Country Park, home to many geophysics and astronomy-related exhibits. (Dorset Council)
https://www.durlston.co.uk/ in Dorset, UK. Durlston was founded by builder George Burt, in the 1880's; he was fascinated by science facts and included many interesting science-related exhibits in the grounds, the centrepiece of which is a gigantic 3-metre diameter globe of the Earth. It seems fitting to choose this as the centrepoint of our conceptual model.

The Heart of the Model

With the Great Globe as our centrepiece, it represents the Sun, of course; however, this aspect of our model is wildly out of scale. The globe is 3 metres across, but our scale Sun should be just 14 centimetres. So, we'll need to use our imaginations here. Moving on, though, we can make things fit better.

MercuryMercury (planet)
An article on Mercury, the planet in our solar system closest to the Sun. (Wikipedia)
https://en.wikipedia.org/wiki/Mercury_(planet)'s orbit conveniently fits on the path around the globe, just under 6 metres from the centre. Mercury itself would be represented by a grain of sand, just half a millimetre across. On the grass around the globe, we would have VenusVenus
An article on Venus, the second planet from the Sun in our solar system, and the planet closest to Earth in size. (Wikipedia)
https://en.wikipedia.org/wiki/Venus, 11 metres from the centre; and the EarthEarth
An article on our home planet, the Earth. (Wikipedia)
https://en.wikipedia.org/wiki/Earth, 15 metres; both scaled to a little over a millimetre. Farther up the grass is MarsMars
An article on Mars, the fourth planet from the Sun. (Wikipedia)
https://en.wikipedia.org/wiki/Mars, 23 metres from the centre, and about ¾ of a millimetre in size.

The Asteroid BeltAsteroid Belt
An article on our solar system's Asteroid Belt. (Wikipedia)
https://en.wikipedia.org/wiki/Asteroid_belt takes up most of the path to the castle, from 25 to 60 metres from the centre. The asteroids themselves would be too small to see at this scale; they would all be microscopic, except for CeresCeres (dwarf planet)
An article on the dwarf planet Ceres, the largest object in the asteroid belt between Mars and Jupiter. (Wikipedia)
https://en.wikipedia.org/wiki/Ceres_(dwarf_planet), the only dwarf planet in the asteroid belt, which would be around a tenth of a millimetre across.

The Big Planets

Beyond the asteroid belt we have JupiterJupiter
An article on Jupiter, the fifth planet from the Sun, and the largest planet in our solar system. (Wikipedia)
https://en.wikipedia.org/wiki/Jupiter, at the lower end of the castle, 81 metres from the globe; this is the first really visible object, at 14 millimetres across.

SaturnSaturn
An article on Saturn, the giant ringed planet, and the sixth planet from the Sun. (Wikipedia)
https://en.wikipedia.org/wiki/Saturn is half-way up to the car park, 150 metres from the start, and 12 millimetres across. This is followed by the two ice giants: UranusUranus
An article on Uranus, the seventh planet from the Sun. (Wikipedia)
https://en.wikipedia.org/wiki/Uranus and NeptuneNeptune
An article on Neptune, the eighth planet from the Sun, and the outermost planet that we know of in our solar system. (Wikipedia)
https://en.wikipedia.org/wiki/Neptune, both along the path to the lighthouse, 298 and 448 metres from the centre, and each about 5 millimetres in size. Neptune also marks the start of the Kuiper BeltKuiper Belt
An article on the Kuiper Belt in our solar system. (Wikipedia)
https://en.wikipedia.org/wiki/Kuiper_belt, which stretches out to about 750 metres from the start. In the nearer part of this belt is PlutoPluto
An article on Pluto, formerly classified as a planet, but now known to be just one of many dwarf planets orbiting the Sun beyond Neptune. (Wikipedia)
https://en.wikipedia.org/wiki/Pluto, represented by a speck just a quarter of a millimetre across.

Going west along the coast path, we pass Sedna90377 Sedna
An article on the trans-Neptunian object Sedna, which orbits the Sun far beyond Neptune. (Wikipedia)
https://en.wikipedia.org/wiki/90377_Sedna and ErisEris (dwarf planet)
An article on the dwarf planet Eris, which orbits the Sun beyond Neptune. (Wikipedia)
https://en.wikipedia.org/wiki/Eris_(dwarf_planet), 1.2 and 1.4 kilometres from the start, and again tiny — Eris is about the size of Pluto, and Sedna just a tenth of a millimetre. The next landmarks are man-made objects: Voyager 2Voyager 2
An article on the Voyager 2 space probe. (Wikipedia)
https://en.wikipedia.org/wiki/Voyager_2 at 2.2 km from the start, and Voyager 1Voyager 1
An article on the Voyager 1 space probe. (Wikipedia)
https://en.wikipedia.org/wiki/Voyager_1 at 2.6 km — as of late 2026. They are, of course, moving, and their models would need to be moved out by about 50 metres per year.

This brings us to the end of our certain knowledge of the solar system, as Voyager 1 is the farthest known object in it.

The Vast Unknown

It's a long, empty gap to the next landmark. 15 km along the coast path, near Tyneham, we get to the hypothetical position of Planet 9Planet Nine
An article on Planet Nine, a hypothetical large planet in the outer region of the Solar System. (Wikipedia)
https://en.wikipedia.org/wiki/Planet_Nine (if it exists, which is very uncertain). This giant planet would be about 4 mm across in our model.

We don't know of anything this far out in our solar system, but the theorised outer frontier is the Oort cloudOort cloud
An article on the Oort cloud, a hypothetical belt of icy objects orbiting at the edge of our solar system. (Wikipedia)
https://en.wikipedia.org/wiki/Oort_cloud. This would begin somewhere about Chesil Beach, over 50 km from our starting point. It stretches out in all directions for over 750 km — this encompasses most of the British Isles, ending only in the Cairngorm mountains — or perhaps farther, even as far out as Oslo.

With this, we're finally out of the solar system. But we have a long way to go to our nearest stellar neighbour, Proxima CentauriProxima Centauri
An article on Proxima Centauri, the closest star to our solar system. (Wikipedia)
https://en.wikipedia.org/wiki/Proxima_Centauri, lost in the Ural mountains.

A Big Deal

Building a scale model of the solar system is a massive undertaking, which is why so few exist — almost all models and diagrams of the solar system that you see fudge the scale in some way, or just ignore it completely.

But I hope this paper scale model exercise has at least given you some insight into why this is so hard.