December 5th, 2021

The Solar System contained within a city

By Dale Woodard on September 25, 2021.

Lethbridge Astronomy photo - Above: The scale model of the planet Jupiter is located on the patio of the Science Commons Building, University of Lethbridge.

Want to take a cruise through the solar system?
All you’ll need is a small part of your day and you won’t even need warp speed.
Through a little bit of creative scaling, the Lethbridge Astronomy Society has brought the entire solar system to Lethbridge.
It starts right in the heart of downtown with the 5.5-meter diameter dome on the Post Building representing the sun.
From there, members of the Lethbridge Astronomy Society calculated how large each planet would be and where its orbit would lie in relation to what historic local landmark.
Earth, for example, is the size of a tennis ball and its orbit falls close to the downtown Fire Station.
Each planet model is sized true-to-scale and placed on a pedestal that carries a plaque with basic facts about the planet and a QR code that links to the Astronomy Society’s website ( for more information.
“This whole project was conceived more than 10 years ago by one of our club members, Klaus Jericho,” said Tom Anderson, president of the Lethbridge Astronomy Society. “There are solar system models similar to this in other places. But the idea of putting it into downtown Lethbridge using the dome on the Post Building came from Klaus. It was really only about two or two-and-a-half years ago that we were able to round up some funding to make this thing a reality.”
The project is funded by grants from the Community Foundation of Lethbridge and Southwestern Alberta, Richardson Oilseed, Telus and Ward Bros. Construction with the University of Lethbridge and the Lethbridge School Division/Chinook High School funding their own models.
When that was in place, the construction of the local solar system took shape.
“You imagine the sun, which is a huge ball of gas in the middle of our solar system, we’re going to shrink that down so it’s now the size of the dome on the post office,” said Anderson. “If the sun was only that big, then how big would the planets be in relation to that and where about would their orbits fly in relation to all of that? So we erected all of these models. They’re all in the ground except for the one at Chinook High School, that will be Saturn. It’ll probably be up in the next week or two. It’s a much more complicated exhibit than the other because Saturn has those magnificent rings.”
The closest planet to the sun, Mercury, is located at the downtown library.
“It’s about half-an-inch plus a bit in diameter,” said Anderson. “The furthest planet from the sun is Neptune and it’s way out in Park Lake, that’s 18 km away. You have this distance of 18 km to the post office dome, which is only five-and-a-half metres in diameter, but that’s a fairly small five-and-a-half metre diametre dome and it’s somehow generating enough gravity to keep this planet in orbit 18 km away. That’s amazing to me. That’s really the point of the exercise, to educate people, help them to understand how big our solar system is and the relationship in size between the different planets and just to have a better grasp of the universe we live in.”
With the sun located at the Post Building, the rest of the solar system took shape.
Venus is located at the old courthouse next to the Sterndale.
“Venus is about the size of the earth, so think of a tennis ball,” said Anderson. “The moon is a correct distance from the model of the earth by the main fire hall just off of Scenic.
Mars is at the Galt Museum, said Anderson.
“We don’t have the asteroid belt, but if we did it would basically be the Old Man River.”
Jupiter is at the science commons at the University of Lethbridge, Saturn is at Chinook High School and Uranus is at Broxburn, while Neptune “orbits” out at Park Lake.
“So you can drive around and see them all in a pleasant morning and afternoon,” said Anderson. “They can do a bike tour out to Neptune and back. Neptune and back is close enough to the distance of a marathon and that opens up some possibilities.”
Anderson noted another interesting tidbit that came about when putting the project together.
“This is kind of a fluke, but it’s kind of cool,” he said. “If you take the scaling ratio for our model, it’s one-in-253 million in the real world. But if you scale the speed of light by that same ratio it works out to walking speed. Sunlight takes about eight minutes to get from the sun to earth and that’s about how long it’ll take you to walk from the post office to the fire station. Walking speed is the speed of light in terms of our model. So if you hop on your bike you’re going warp speed.”
Next up will be putting plaques at each of the planet installations.
Currently, there are QR codes at each of the locations.
“If you scan that with your phone it takes you to our website and there’s all kinds of additional information on the website about the planets,” said Anderson. “There’s a section with quick facts or if you want to go for a much more in-depth discussion about characteristics of the planet, that’s on there, too. You can see all that directly at the website or if you’re at one of the pedestals and you want to scan the QR code that will get you there, too.”
Anderson said the solar system will be a permanent part of the city.
“It’ll be a good draw for creative business opportunities and school groups can have passports and they can have ambassadors for each planet, learn about the planet and tell their classmates about the planet.”
Visit for more about the club and a description of the project.

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