You cannot protect what you do not know
In Porto Alegre, within the walls of a Jesuit school, a mechanical model of the solar system has kept turning for a century — one of only five such instruments known to exist in the world, and the only one still in motion. Built in Paris in the era of Émile Bertaux and acquired by the Museu Anchieta de Ciências Naturais in 1926, the planetarium endures as a rare confluence of craft, science, and institutional devotion. Its survival asks something of us: that we consider what it means to preserve not just objects, but the particular ways human beings once reached toward understanding the cosmos.
- A mechanical planetarium believed to be one of only five in existence continues to function inside a Porto Alegre school museum — a distinction no other institution in Brazil can claim.
- While four known counterparts sit dormant in European collections and auction houses, this single working example quietly demonstrates the movements of the solar system to visiting schoolchildren.
- The museum's 130,000-specimen collection — spanning arachnids, preserved fish, fossils, and taxidermied fauna — amplifies the stakes: this is a living archive that took generations to build and demands active stewardship to survive.
- Curator Alana Cioato frames the mission urgently: environmental awareness begins with direct encounter, and a school museum is one of the few places where that encounter can happen at the right age.
- Infrastructure renovations launching in December 2025 will temporarily displace exhibitions until 2028, but the planetarium and collections will remain accessible — free of charge, by appointment — even amid the construction.
Inside Colégio Anchieta in Porto Alegre, a machine acquired in 1926 has been turning ever since. It is a mechanical planetarium — a physical model of the solar system designed to simulate the movement of planets through space — and researchers have determined it is the only one of its kind still functioning anywhere in Brazil.
The instrument is believed to have been crafted by Émile Bertaux, a Parisian maker of globes and geographical instruments who lived from 1840 to 1903. Only five examples of this particular planetarium are known to exist worldwide. The other four remain in Europe — in French galleries, a private collection, and Milan's Leonardo da Vinci National Museum of Science and Technology. Researchers from two Brazilian universities documented this finding in the Iberoamerican Journal of Historical-Educational Heritage.
Curator Alana Cioato speaks of the machine with the quiet pride of someone entrusted with something irreplaceable. She recounts students who have visited other museums and returned to report, with visible satisfaction, that their school's version actually works. That working condition is precisely what makes the planetarium the centerpiece of the current exhibition.
The museum surrounding it is vast. Founded in 1908, the Museu Anchieta de Ciências Naturais holds roughly 130,000 cataloged specimens — 118,000 arachnids, 12,000 alcohol-preserved fish from Brazil, Uruguay, and Argentina, taxidermied vertebrates, fossils, shells, and mineral samples gathered from across the continent and beyond. Cioato argues that collections like these serve a purpose deeper than display: when children encounter the physical evidence of life and geology, their relationship to the natural world shifts. You cannot protect what you do not know.
Beginning in December 2025, the building will undergo renovations to improve accessibility and infrastructure, with work expected to continue through 2028. Exhibitions will temporarily relocate within the campus but remain open. The planetarium will keep turning through it all. Visits are free, guided, and available by advance booking Monday through Friday — a working window into how people once mapped the heavens, and how that mapping still matters.
In a school museum in Porto Alegre sits a machine that few people in Brazil have ever seen working. It is a planetary device from 1926—a mechanical model of the solar system, built to show how the planets move through space. The Museu Anchieta de Ciências Naturais, housed within Colégio Anchieta, has kept this rare instrument in functioning condition for a century. As far as researchers can determine, it is the only one of its kind still working anywhere in the country.
The machine is believed to have been manufactured by Émile Bertaux, a Parisian maker of globes and geographical instruments who lived from 1840 to 1903. Only five examples of this particular planetarium are known to exist in the world. Four remain in Europe—two in French auction houses and galleries, one in another French collection, and one in Italy's Leonardo da Vinci National Museum of Science and Technology. The fifth, the one that works, is here in Rio Grande do Sul. Researchers from the Federal University of Rio Grande do Sul and the University of Vale do Taquari documented this finding in a recent article published in the Iberoamerican Journal of Historical-Educational Heritage.
Alana Cioato, the museum's curator, speaks about the machine with the kind of pride that comes from stewardship of something genuinely irreplaceable. She notes that students who have visited other museums often return and tell her, with visible satisfaction, that their own museum's version actually functions. The planetarium is one of the centerpieces of the current exhibition precisely because of its rarity and its working condition—a distinction that sets this place apart.
The museum itself is far larger than its most famous artifact. Since its founding in 1908, it has accumulated approximately 130,000 cataloged specimens. The collection includes 118,000 arachnids—spiders, scorpions, harvestmen, and ticks—alongside 12,000 fish preserved in alcohol, sourced from Brazil, Uruguay, and Argentina. There are also taxidermied reptiles, amphibians, birds, and mammals. Fossils of vertebrates, invertebrates, and plants fill the cases, along with shells and samples of minerals and rocks gathered from across Brazil and beyond. It is the kind of collection that takes generations to build and only moments to lose if not properly maintained.
Cioato emphasizes why school museums like this one matter. They serve a purpose that extends beyond mere display. When children see the animals and plants, when they encounter the physical evidence of life and geology, something shifts in how they understand their relationship to the natural world. Environmental education, she argues, begins with seeing. You cannot protect what you do not know. A museum, especially one embedded in a school, becomes a place where that knowing can happen.
The building itself will soon undergo significant renovation. Starting in December, work will begin to improve accessibility and infrastructure. The project is expected to continue through 2028. During this time, the exhibitions will relocate temporarily to another building on the campus, but they will remain open to visitors. The planetary machine will continue its slow, mechanical demonstration of the cosmos, indifferent to the construction happening around it.
Visits are free for both the general public and school groups, though advance scheduling is required. The museum operates Monday through Friday, mornings from 7:30 to noon and afternoons from 1 to 6 p.m. Those interested can call or email to arrange a guided tour. It is the kind of place that rewards the effort of planning ahead—a working window into how people once understood the heavens, and how they still might.
Citas Notables
Students who visit other museums often come back and tell us with pride that our machine actually works— Alana Cioato, museum curator
When children see the animals and plants, something shifts in how they understand their relationship to the natural world— Alana Cioato, on the role of school museums in environmental education
La Conversación del Hearth Otra perspectiva de la historia
Why does a machine from 1926 still matter? It's just a model of the planets.
Because it works. Almost nothing from that era still functions. Most planetariums like this one ended up in attics or were discarded. This one has been running for a hundred years.
But there are planetariums everywhere now—digital ones, immersive ones. What does a mechanical model teach that a computer can't?
Something different. You can see the gears, the logic of it. You understand that someone figured out how to make the invisible visible without electricity. There's honesty in that.
The curator mentioned environmental education. How does a 1926 machine teach kids to care about nature?
It doesn't directly. But it's part of a larger collection—130,000 specimens. When you see a preserved fish from the Paraná River, or a taxidermied bird, you're holding evidence. The machine is just the most elegant piece of that evidence.
The museum is closing for renovations until 2028. Isn't that a loss?
It's temporary. The exhibitions move to another building. The real risk would be doing nothing—letting the infrastructure decay until the collection itself is at risk. Sometimes you have to close to survive.
Why is this story important now, in 2026?
Because we're at a moment where we're deciding what to preserve and what to let go. This museum is choosing to invest in its future. That's a statement about what we value.