Adler Planetarium

Listen for a moment. Out here, at the tip of this narrow strip of land, the city noise drops away. You hear wind off Lake Michigan, the slap of small waves against the stone edge, and gulls arguing overhead. Turn around and the whole Chicago skyline stands in a single line across the water. Then turn back. In front of you is a low, solid building of reddish stone. It looks less like a museum and more like a vault built to hold the sky.

This is the Adler Planetarium. When it opened in 1930, it was the first modern planetarium in the Western Hemisphere. That is worth a pause. Before this building, most Americans had never seen a realistic night sky projected indoors. Here, for the first time on this side of the Atlantic, a crowd could sit in the dark and watch the stars rise, turn, and set above them on a curved ceiling. People came in very large numbers to see it.

The idea came from Max Adler, a Chicago businessman who had made his fortune as an executive at Sears, Roebuck and Company. He had travelled to Germany in the 1920s. There he saw a new kind of machine, built by the optical firm Zeiss, which could project the stars onto a dome. He was deeply impressed. He came home determined that Chicago should have one too, and he paid for much of it himself. The city got its planetarium, and his name has stayed on the door.

Now look closely at the shape of the building. It has twelve sides. That number is not an accident. Twelve is the number of the signs of the zodiac, the band of constellations that the sun, moon, and planets appear to travel through across the year. The architect, Ernest Grunsfeld Junior, designed a structure that carries the sky in its very floor plan. Walk slowly around the outside and you are, in a sense, walking through the calendar.

The style is Art Deco, the bold, geometric look that was popular in the 1920s and 1930s. You can see it in the clean vertical lines, the stepped outline, and the way the dome sits low and heavy rather than floating high. The stone itself is granite, quarried in the American Midwest. Look at its colour. It is not one shade but many, with streaks of pink, red, and grey. In changing light, the walls seem to shift tone through the day.

Here is a detail most visitors walk straight past. At the corners of the building, look for bronze plaques set into the stone. They were made by the sculptor Alfonso Iannelli, and they show the planets in a stylised, almost ancient way. Each one is a small piece of art. Many people photograph the skyline behind them and never notice what is on the wall. Take a minute to find them. They reward a close look.

The timing of the opening matters too. In 1930, the Great Depression had already begun. Money was short across the country. Yet the planetarium opened its doors, and a few years later Chicago hosted a large world's fair called A Century of Progress, held along this same lakefront in 1933 and 1934. The fair celebrated science and the future. The planetarium fit that mood perfectly. Many fair visitors made their way here to look up.

The ground under your feet has its own story. This peninsula was not always here. Much of Chicago's lakefront is built on fill — land created by humans, pushed out into the lake over many decades. This spot is the northern end of what Chicagoans call Northerly Island. Today it forms part of the Museum Campus, a lakeside park shared with a natural history museum and a large aquarium. Few cities place science museums so close together, with water on almost every side.

Inside, the planetarium is much more than a single dome. Over the years it has grown, with newer wings added behind the original stone building. The sky theatres use digital projection now, filling the dome with images of planets, galaxies, and deep space. But the museum also holds a large historical collection of scientific instruments. There are old astrolabes, globes, sundials, and telescopes, some of them centuries old. They show how people measured the heavens long before electric light or computers.

An astrolabe, if you have not met one, is a flat brass instrument that ancient and medieval astronomers used to calculate the position of the stars and the time of day. It looks like a decorated metal disc with turning rings. Seeing one in person is surprising. They are often beautiful, engraved with fine lines and lettering, and small enough to hold in two hands. They were the pocket computers of their age, and skilled makers spent a long time crafting each one.

The museum also tells the story of human spaceflight. One of its treasures is the Gemini 12 capsule, a real spacecraft that carried two American astronauts into orbit in the 1960s. One of them was Jim Lovell, who later flew on the Apollo missions. When you stand beside it, notice how small it is. Two adults sat inside, shoulder to shoulder, for days. It makes the courage of those early flights feel very real and very human.

Before you leave, look for the large bronze sculpture on the grounds nearby. It is a work by the British artist Henry Moore called Man Enters the Cosmos. It is also a working sundial. On a clear day its shadow marks the hour, using the same sun that the astronomers inside have studied for generations. It is a quiet link between the oldest way of telling time and the modern science of the sky.

Now take one more look around. Behind you, the towers of the city catch the light. Ahead, the lake stretches to a horizon with nothing on it but water and air. At night, this is one of the darkest places close to downtown, and on a clear evening you may see a few bright stars above the stone dome. As you walk back along the shore, glance up. The same sky that started all this is still there.