A Legacy In Motion

For more than a century, Yerkes has been a place of discovery, ambition, and breakthroughs. This is the story of how it came to life and the people who shaped what we know about the universe.

It Started With Two Lenses

In 1892, a young astrophysicist named George Ellery Hale learned of two 40-inch lens blanks sitting unused in a warehouse. With the support of University of Chicago president William Rainey Harper and a major investment from Charles Tyson Yerkes, that vision began to take shape.

When Yerkes opened in 1897, it brought together research, experimentation, photography, and education. Over the decades that followed, it attracted some of the most influential figures in astronomy, shaping how we understand the universe. What you see today is built on that legacy.

Land and Sky Acknowledgement

At Yerkes, we recognize that our work takes place on the traditional homelands of the Potawatomi, Ho-Chunk, and Menominee peoples. For generations, these Nations have observed the skies and contributed deep knowledge to our understanding of the cosmos.

Though these communities were displaced, their cultural and celestial connections to this land continue. As we explore the universe, we honor their past, present, and future contributions and pay respect to the people, cultures, and Elders who have shaped both astronomy and the stewardship of this land.

The Story Over Time

From its earliest beginnings to today, each moment builds on the last, shaping the discoveries, people, and legacy that define Yerkes.

1893

The tube of the Great Refractor is exhibited at the World’s Columbian Exposition in Chicago, offering a first glimpse of what’s to come.

1895

Construction of Yerkes Observatory begins.

1897

Yerkes opens and is formally transferred to the University of Chicago, marking the start of a new era in astronomical research.

1909

An early photograph of Pluto is captured at Yerkes, though its significance isn’t recognized at the time.

1911

Yerkes is surpassed as home to the world’s largest telescope by the Mt. Wilson reflector, marking a shift in astronomical technology.

1921

Albert Einstein visits Yerkes during his first trip to the United States.

1943–1953

The Yerkes MKK spectral classification system is developed, becoming a foundational method for understanding stars.

1951

Gerard Kuiper proposes the existence of what is now known as the Kuiper Belt, a region of icy bodies beyond Neptune.

1960

Twin reflecting telescopes are added to the eastern towers, expanding the observatory’s capabilities.

1983

Subrahmanyan Chandrasekhar is awarded the Nobel Prize in Physics for his work on stellar structure.

1991

Research at Yerkes contributes to the development of adaptive optics, improving how telescopes observe space.

2020

The University of Chicago transfers Yerkes Observatory and surrounding land to Yerkes Future Foundation, ensuring its preservation and future.

The Who's Who of Astronomy

If astronomy had a walk of fame, it would be here. Yerkes has drawn some of the most influential minds in science, many of whom helped shape how we understand the universe.

E. Margaret Burbidge

Astronomer at Yerkes, 1951-1953 & 1957-1962. Burbidge's 1957 landmark paper proved that most heavy elements found on earth and in humans were formed in stars. She challenged sexism in science and was the American Astronomical Society's first female president.

Kyle Cudworth

Astronomer at Yerkes, Director of Yerkes, 2001-2012. Cudworth compared photograph images of star clusters taken 80 years apart to measure star movement within the clusters. His observations facilitated estimating the distances to the clusters.

Carl Sagan

Graduate student at Yerkes, 1956–1960. Sagan studied under planetary scientist Gerard Kuiper and later became one of the world’s most recognizable science communicators, bringing the wonder of the cosmos to millions.

Nancy Grace Roman

Graduate student and research assistant at Yerkes, 1946–1954. Roman conducted research in stellar spectroscopy at Yerkes before becoming NASA’s first Chief of Astronomy. Her namesake telescope launched in August 2026.

Gerard Kuiper

Astronomer and twice director of Yerkes, 1937–1960. Often called the father of planetary science, Kuiper’s research transformed our understanding of the solar system. His work led to the identification of the region beyond Neptune now known as the Kuiper Belt.

Subrahmanyan Chandrasekhar

Astronomer at Yerkes, 1936–1950. “Chandra” made groundbreaking contributions to the study of stellar structure, stellar dynamics, and the life cycles of stars, work that would later earn him the Nobel Prize in Physics.

Otto Struve

Astronomer at Yerkes, 1921–1947. Struve arrived in America as a refugee following the Russian Revolution and began work at Yerkes as an observatory assistant. Within little more than a decade, he earned his Ph.D. and rose to become director of the observatory.

Edwin Hubble

Graduate student at Yerkes, 1914–1917. Hubble transformed astronomy by demonstrating that galaxies exist beyond the Milky Way and discovering the universe is expanding, fundamentally reshaping our understanding of the cosmos.

Mary Ross Calvert

Astronomical computer and astrophotographer at Yerkes, 1905–1946. As one of the many women whose mathematical expertise supported the observatory’s research, Calvert contributed to the cataloging and study of dark nebulae and other celestial objects.

Sherburne W. Burnham

Astronomer at Yerkes, 1897-1914. Court reporter by day and amateur astronomer by night, Burnham received an appointment at Yerkes in 1897 and is credited with discovering 1,340 binary stars.

Charles Tyson Yerkes

Major donor, 1892. A powerful Chicago financier best known for developing much of the city’s elevated railway system, Yerkes funded the initial construction of the observatory, helping turn Hale’s vision into reality.

Henry Ives Cobb

Architect of Yerkes Observatory, 1895. Known for designing many of the Gothic-style buildings on the University of Chicago campus, Cobb brought an appreciation for classical architecture to Yerkes, giving the observatory its distinctive character.

George Ellery Hale

Associate Professor of Astrophysics at the University of Chicago, 1893. Widely considered the driving force behind Yerkes Observatory, Hale envisioned a world-class center for astronomical research and sketched many of the ideas that shaped its design and purpose.

William Morgan

Astronomer at Yerkes, 1926-1994. Morgan was an architect of the Yerkes (MKK) stellar classification system. His work helped astronomers better understand the characteristics and evolution of stars. In 1951, he discovered the spiral arm structure of the Milky Way galaxy.

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