Beyond its observatory and exhibits, the Adler cares for rare artifacts — some dating back a thousand years.

Credit: The Adler Planetarium

The Adler Planetarium in Chicago.

This May marks the 93rd anniversary of the Adler Planetarium — the first planetarium built in the Western hemisphere. Located on the windy shores of Lake Michigan in Chicago, the facility was established by Max Adler, who in 1928 gave $500,000 to support its construction — nearly $9 million today.

After retiring from Sears, Roebuck & Co., the company that served as the namesake of Chicago’s famous Sears Tower (now Willis Tower), Max Adler wanted to spend his wealth on Chicago’s community — and a fateful visit to Germany gave him his big idea. There, in Munich, he saw a new Zeiss projection-based planetarium.

He was determined to bring the landmark technology to the United States. By then, the projection-based planetarium was the hot new thing in Europe, with 15 in Germany alone. Previous planetarium designs had relied on complex mechanical systems, but the projection-based system was more robust and offered the potential for new types of planetarium shows.

Designated as a National Historic Landmark in 1987 and an APS Historic Site in 2019, the Adler today is an astronomical gem. The facility boasts three planetarium domes, a publicly accessible observatory that’s popular with researchers, exhibit and educational spaces, and a collection of over 6,000 artifacts, books, and manuscripts related to astronomy and astrophysics, many of which can be viewed online.

“I like to say we’re small but mighty,” says Chris Helms, the Adler’s senior collections manager.

The Adler has seen tremendous growth and change over time, including in its collections. When Max Adler first opened the facility on May 12 — his birthday — in 1930, he “envisioned the museum not just as a space that you would come and see cool exhibits and sky shows,” says Helms, but as “a place for serious research.”

Credit: Carl Zeiss Works / The Adler Planetarium

Visitors line up on the Adler Planetarium’s opening day in May 1930.

So when Adler learned that art dealer and auctioneer Antonius W. M. Mensing was selling a collection of astronomical instruments and antiques in Amsterdam, he bought the lot.

Nearly a century later, the Adler continues to add items to its collections through formal acquisitions each year. “We’re probably top three or four in the world in terms of the importance and the rarity of the objects that we do have,” says Helms.

Helms says that the oldest items in the Adler’s collection include a Mesopotamian terracotta carving of a lion, long suspected to be a depiction of the constellation Leo the Lion, as well as an astrolabe — an early navigational instrument that ship captains used to determine their latitude based on stars — that dates to the twelfth century.

Helms’ personal favorite is a filigree celestial sphere, dating to the 1500s, which is on display in the museum. The brass sphere is about 16 inches in diameter and has over 1,000 stars punched into it. “The constellations are your typical Western and Ptolemaic constellations, like Perseus and Hercules,” he says, except that “they’re made with a Middle Eastern art style. So it’s this really awesome mix of Western star charts and Eastern art.”

As a collections manager, Helms says that metal objects like the celestial sphere tend to be the easiest to care for. In fact, the Adler possesses several brass and bronze artifacts with preserved fingerprints dating back 400 years or more — possibly the fingerprints of the master craftspeople who made them.

But caring for objects made of wood, bone, ivory, paper, or plastic is more of a challenge, Helms says, especially in a building that wasn’t originally designed for climate control. For example, the Adler’s collection of hand-painted books requires careful attention. “Those are always a huge challenge, especially when we’re building exhibits,” he says, because the cases in which the books are housed require finely tuned light, temperature, and humidity levels.

Similarly, one item you’ll likely never see in person is a stunning Chinese star map, measuring eight by five feet. The multi-panel map “is dyed almost entirely with blue ink, and our conservationists say we’re allowed to show it for 6 weeks every 14 years,” says Helms, “because any amount of light would hit the blue pigment and start to fade it pretty much immediately.”

Credit: The Adler Planetarium

“Hun T’ien Yi T’ung Hsing Hsiang Ch’uan T’u,” a Chinese star map dating back to the 1600s — one of many rare artifacts in the Adler’s collections.

The Adler also has an assortment of space-related plastic objects, including about 40 space flight models donated by Robert Gilruth, the former director of NASA’s manned space flight program, as well as a space suit helmet and EVA gloves. The helmet and gloves “were designed to work really well in space for a little while — but not to survive for hundreds or thousands of years” in a museum collection, notes Helms.

“The one thing we don’t know how to do [in artifact conservation] is prevent plastic from deteriorating,” he says. And because plastics outgas as they deteriorate, they can be damaging to other objects in the collection.

Thankfully, the Adler has plans for an upgrade to its HVAC system, in addition to new storage cabinets in its below-ground collections spaces. Even though most of these spaces aren’t accessible to the public, it’s possible to secure a tour. “We’re always working on ways to give people more behind-the-scenes viewing opportunities,” says Helms. The Adler’s Google Arts & Culture page offers another way to interact with their collections from afar.

For Helms, creating opportunities for the public to access the Adler’s collections and ensuring that historically significant artifacts survive for generations to come is deeply meaningful.

“[The objects] represent individuals, they represent societies, they represent cultures,” he says. “They represent stories that are not just fun to tell, but important to tell, and so maintaining them as physical manifestations of those stories is important.”

“It’s why I do what I do.”

If you’re attending the 23rd biennial conference of the APS Topical Group on the Compression of Condensed Matter in Chicago this June, make sure the Adler is a stop on your list!

Liz Boatman is a staff writer for APS News.