More than a century of science

The Earth & Planets Laboratory (EPL) traces its origins to the establishment of Carnegie’s Department of Terrestrial Magnetism (DTM) and Geophysical Laboratory (GL) in 1904 and 1905, respectively. DTM’s original mission was to investigate the magnetic and electrical fields of the Earth, while GL pioneered experimental studies of rock and mineral formation and the Earth’s interior.

In 2020, after three decades of sharing the Broad Branch Road campus and increasingly close collaboration, the two departments united to form the Earth & Planets Laboratory.  

Over time, and through many historic moments in our country's history, the department’s research agendas evolved, contributing substantially to the rise of several new scientific disciplines as they grew, such as isotope geochronology, biogeochemistry, mineral physics, astrobiology, and the increasingly multidisciplinary study of exoplanets.

Throughout our history, both departments—and now EPL—subscribed to a multipronged and collaborative approach to science that encourages a mix of observational, experimental, theoretical, and computational research. Even as scientific goals change over time, it is this spirit that allows our researchers to freely tackle the most challenging questions about our planet and its place in the universe from all angles.

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Our Founding Departments

Our History by Category

Discovering dark matter

After observing dozens of galaxies by the 1970s, Vera Rubin and her colleagues found that something other than the visible mass was responsible for the stars’ motions. Each spiral galaxy is embedded in a “halo” of dark matter—material that does not emit light and extends beyond the optical galaxy. They found it contains 5 to 10 times as much mass as the luminous galaxy.

As a result of Rubin’s groundbreaking work, it has become apparent that more than 90 percent of the universe is composed of invisible material—dark matter and dark energy.

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Hand-tinted lantern slide of Galilee

First world magnetic survey

At the turn of the 20th Century, scientists knew that the earth's Earth's magnetic field varied across the globe and over time, causing compasses to go awry and point as much as several degrees away from true north. Sailors found this inconvenient, but it was the scientific community that was truly perplexed.

The Department of Terrestrial Magnetism—one of the original departments that now make up the Earth & Planets Laboratory—was established by the Carnegie Institution of Washington in 1904 expressly to investigate the magnetic field of the earth and its variation, both over space and over time. Two vessels were employed in this investigation, first the Galilee, then the custom-built non-magnetic Carnegie.

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Bank of resistors (lower left corner) for controlling the temperature of an electric furnace in the laboratory of Day and Sosman

Establishing experimental petrology

Experimental petrology owes much to the foundation of the Geophysical Laboratory in 1905.

The Laboratory was established at a time when top igneous petrologists wanted to gain “exact science” prestige for their field—like chemistry or physics. However, while a respected area of geoscience research today, experimental petrology was largely ignored and unappreciated until the 1940s.

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A proximity fuze at the left compared with a clockwork fuze at right

The proximity fuze and WWII

During World War II, our efforts shifted to national defense projects, notably the development of the proximity fuze under Merle A. Tuve’s leadership.

The proximity fuze revolutionized warfare for the United States during World War II. The fuze used Doppler radar to allow an artillery shell to detonate when it was near its intended target. This allowed for more precise targeting and optimal effectiveness. Until the development of the proximity fuze, a detonation relied on physical contact, a timer, or an altimeter. 

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Fission demonstrated at DTM on 28 January 1939

Smashing the atom

On January 28, 1939, our campus became one of the first places in the United States to demonstrate uranium fission. Only two days earlier, news of fission became public knowledge at the Fifth Washington Conference on Theoretical Physics, sponsored jointly by the Carnegie Institution and George Washington University. The experiment demonstrated it as a nuclear as well as a radio-chemical phenomenon. As it happens, Niels Bohr, Enrico Fermi, and other conference attendees were present to witness this historic event.

(Left to right: Robert Meyer, Merle Tuve, Enrico Fermi, Richard Roberts, Leon Rosenfeld, Erik Bohr, Gregory Breit, and John Fleming.)

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