Zielona Góra participatory budget 2027 · project no. 62
A Walk Through the Solar System
The universe is so vast that it is hard to grasp. Even the Sun, our nearest star, is 150 million kilometres away, and to us that is just a number. This project turns it into a walk.
The dome of the Wenus planetarium will be the Sun, and the planets from Mercury to Jupiter will be set out across Zielona Góra at the same scale. Almost a kilometre and a half from the dome, the Earth will be the size of a small melon. Why so small? Because the Sun really is 109 times wider than the Earth. Jupiter, as tall as an eight-year-old, will stand in the park in Kiełpin. A Solar System you can walk, or cycle.
What it is
- 1
The Sun is already built
The dome on the roof of the Wenus planetarium is about 13 metres across. In this model, it is the Sun.
- 2
One scale for everything
The Sun, the planets and the distances between them are all scaled down by the same factor, about 110 million. The Earth is then about 12 centimetres across, and its orbit runs almost a kilometre and a half from the dome.
- 3
Six sculptures on one route
Mercury, Venus, the Earth, the Moon, Mars and Jupiter, all at the same scale, each with a plaque carrying a description and a QR code. Across the road from the planetarium, a board will map the whole route.
Where the sculptures will stand
The numbers mark the sculptures. Each band is a planet’s orbit at the model’s scale: its inner edge is as close as the planet comes to the Sun, its outer edge as far as it goes.
Curious what a smaller or bigger Sun would do? Try the scale explorer. →At this scale, light travels at 10 km/h, an easy jogging pace. It leaves the dome and passes the Earth after 8 minutes and 19 seconds, which is how long sunlight really takes to reach us. It gets to Jupiter in Kiełpin in three quarters of an hour.
Why vote for it
- 1
Every drawing of the Solar System lies.
In books the planets sit close together, side by side, because otherwise they would not fit on the page. At this scale, with a Sun the size of the planetarium dome, the Earth is a small melon almost a kilometre and a half away. A page cannot show that, but you can walk it.
- 2
It is a free lesson in the open air.
For schools, nurseries and families: no tickets, no booking, no opening hours, all year round. The plaques carry real diameters and distances to compare, and a QR code leads to a description and a map.
- 3
It ties together what the city already has.
It links the planetarium, the Palm House, the Zielona Strzała cycle path, Zielony Przystanek and the park in Kiełpin into one route, for a walk with children or a bike ride.
- 4
Once built, it lasts.
No power, no screens, nothing to run. The model will not go out of date either: the real planets will keep their distances from the Sun for billions of years to come.
Vote for project no. 62
11–24 November 2026
In Zielona Góra’s participatory budget, residents decide by vote which projects the city pays for. Every resident can vote, at any age: children too.
- 1
From 11 November, go to the voting site, zielonagora.konsultacjejst.pl (in Polish).
- 2
Among the investment projects (projekty inwestycyjne), choose no. 62, “Spacer przez Układ Słoneczny”.
- 3
Enter your details and a mobile number, then confirm the vote with the code sent by text message.
Everyone has two votes: one for an investment project (something built) and one for a social project (activities rather than things). Ours is an investment project, so your social vote is free for any social project you like.
Only residents of Zielona Góra can vote. If you live elsewhere, the best way to help is to send this page to someone who lives in Zielona Góra.
The biggest help is sending this page to someone in Zielona Góra: family, neighbours, the parents’ chat for your child’s class.
Add a reminder to your calendar so you don’t forget to vote.
The event goes only into your own calendar; this page keeps no record of you.
The route, from the Sun to Jupiter
Each sculpture is planned where its planet’s orbit falls at this scale, in a place worth visiting anyway. All the sites are on city land.
Photo 1 of 2
The Sun
The Wenus planetarium dome
- Diameter
- 13 m
The dome on the roof of the Kepler Science Centre, home of the Wenus planetarium (wenus is Polish for Venus). Across al. Konstytucji 3 Maja, a board will describe it and map the whole route.
Photo 1 of 3
1Mercury
The Palm House
- Diameter
- 4.6 cm
- Size
- like a lime
- From the dome
- 532 m
On Wine Hill, with the dome in view. The smallest planet and the closest to the Sun: its year lasts 88 days.
From the previous point: 9 min on foot, 3 min by bike
Photo 1 of 3
2Venus
The Zielona Strzała cycle path, by ul. Nowa
- Diameter
- 11.3 cm
- Size
- like a small grapefruit
- From the dome
- 1,010 m
Venus is almost as big as the Earth. It is the brightest “star” in the sky, the one you see shining in the evening or before dawn.
From the previous point: 21 min on foot, 7 min by bike
Photo 1 of 2
3The Earth
Zielony Przystanek
- Diameter
- 11.9 cm
- Size
- like a small melon
- From the dome
- 1,396 m
In Jędrzychów, by the benches, a short way from the Zielona Strzała cycle path. The Earth’s axis will be tilted at 23.4°, as it really is, which is what gives us the seasons.
From the previous point: 6 min on foot, 2 min by bike
Photo 1 of 2
3The Moon
Zielony Przystanek
- Diameter
- 3.2 cm
- Size
- like a walnut
- From the Earth
- 3.6 m
The Moon is not “right next to us” at all: almost 30 Earths would fit between the two. In the photos it is played by a ball of yellow cheese. Yes, we know. But the size is right.
Photo 1 of 3
4Mars
The woods by ul. Botaniczna
- Diameter
- 6.3 cm
- Size
- like a tangerine
- From the dome
- 2,281 m
Where the Zielona Strzała cycle path meets ul. Botaniczna. Mars is about half as wide as the Earth, and its axis is tilted at almost the same angle.
From the previous point: 25 min on foot, 7 min by bike
Photo 1 of 2
5Jupiter
The park in Kiełpin
- Diameter
- 1.31 m
- Size
- as tall as an eight-year-old
- From the dome
- 7,492 m
Almost due south of the dome, more than 5 km past Mars. Jupiter is bigger than all the other planets put together: more than 1,300 Earths would fit inside it.
From the previous point: 88 min on foot, 31 min by bike
The walk from the dome to Mars is about 4.5 km, roughly 60 minutes. The whole route to Jupiter is about 11.2 km on foot, some 2.5 hours. By bike it is a little longer, about 12.5 km, and takes under an hour at an easy pace. Venus and Mars will be right beside the Zielona Strzała cycle path, the Earth and the Moon a short way from it, and from there cycle paths lead on to Kiełpin.
What the sculptures could look like
The four smaller planets and the Moon are balls at the model’s scale, set like a globe in a ring that holds them by both poles. Unlike a globe, they are fixed for good: they cannot be lifted out or turned.
- 1A ball at the model’s scale; the Earth’s is 11.9 cm across.
- 2A stainless-steel ring, bolted in place.
- 3The axis tilted as it really is: the Earth 23.4°, Mars 25°.
- 4A plaque with the name, the real diameter, the distance from the Sun and a QR code to the map.
- 5A concrete post, about a metre tall.
This is a proposal: the final shape and materials will be settled when the sculptures are designed. The balls could be 3D prints, protected against UV light and painted in the planets’ colours. Jupiter, 1.31 m across, would be a large-format 3D print.
Questions and answers
Who can vote?
Every resident of Zielona Góra, at any age. Everyone has one vote for an investment project and one for a social one.
Why is the planetarium dome the Sun?
Because it is already there. It is about 13 metres across and in the middle of the city, in a place people already associate with the sky. Nobody has to build a Sun, and the dome is easy to see as you walk nearby or go past by car or bus.
Why stop at Jupiter?
At this scale Saturn would stand more than 13 km from the dome, beyond the city boundary. The participatory budget only pays for things on city land, so the model ends with Jupiter in Kiełpin, the furthest planet that fits inside Zielona Góra.
What would it cost?
The application puts it at PLN 274,500 including VAT, with the design documentation and installation.
Who will look after it?
The city, as it does benches and monuments: the sculptures will be its property. They need no power and have no moving parts, so keeping the ground around them tidy is enough.
What if someone damages or steals them?
The small balls are locked into stainless steel rings with tamper-proof fixings: without special tools they cannot be lifted out or turned. Jupiter will be large and fixed firmly to a foundation.
Is it really to scale?
Yes, twice over: the sizes of the planets and their distances from the dome are scaled down by the same factor, about 110 million. Orbits are not perfect circles, so each sculpture stands at a distance its planet really reaches from the Sun.
Has anyone done this before?
Yes. The best known is the Sweden Solar System: the Sun is an arena in Stockholm, and the planets stretch north from there, the outer ones hundreds of kilometres away. Many towns in Germany and Switzerland have planet walks too.
When would it be built?
If the project wins, it goes into the city’s budget for 2027; the city then commissions and installs the sculptures, on a timetable it sets.
Whose idea is it?
A Zielona Góra resident who likes astronomy, and likes making ideas like this one happen even more. He runs Slow Squares, the daily logic-puzzle site this page belongs to, but submitted the project as a private individual.