Carnegie geochemist Erik Hauri, whose work upended our understanding of the Moon’s formation and the importance of water in Earth’s interior, died Wednesday in North Potomac, MD, following a battle with cancer. He was 52.

Hauri joined Carnegie as a staff scientist in 1994 and spent nearly 25 years investigating the geochemistry of the Earth, Moon, and other celestial objects.  Hauri had a particular interest in water, which he called the most-important molecule in our Solar System, saying that understanding where it came from and how it got distributed among the planets and various other bodies would unlock the secrets of how our Solar System evolved.

Scientists had long thought that the Moon was “bone dry”—depleted of water by the violent events of its formation. In 2008, Hauri and his colleagues revealed that tiny beads of lunar volcanic glass collected during the Apollo missions contained water. Three years later, he led the team that discovered water in the Moon’s interior—and not just a little bit of water. In fact, they found that the lunar mantle is as wet as our own and went on to demonstrate in 2013 that the Moon’s abundant water supply originated from the Earth.

These findings called into question longstanding theories of the Moon’s formation and researchers, including Hauri’s colleagues at Carnegie’s Department of Terrestrial Magnetism, are still working to reconcile a wet Moon with the prevailing lunar origin story.

“Erik’s dedication to advancing the capabilities of modern instrumentation allowed him to disprove a 40-year-old assumption that the Moon contained no water,” said Richard Carlson, Director of the Department of Terrestrial Magnetism. “His work on the water contents of a variety of samples from the Earth, Moon and meteorites greatly advanced our understanding of the important role that water plays not only in biological life, but in the dynamics of planetary interiors.  His insight into these questions will be sorely missed.”

Although Hauri was the first member of his family to attend college, he graduated with honors from the University of Miami and went on to complete a Ph.D. in geochemistry from MIT and the Woods Hole Oceanographic Institution in just four years.

In nominating Hauri for an early career achievement recognition from the American Geophysical Union, one of his thesis advisors, Stanley Hart, said that during the graduate school interview process, he confided in Hauri that he would be leaving MIT in two years. According to Hart, Hauri responded: “Oh, that’s OK. … I think I can learn all you have to teach in two years!”

In 2000, Hauri won that award—the James B. Macelwane Medal—in addition to the Houtermans Award from the European Association of Geochemistry in 1999. He later was named a fellow of both organizations, as well as of the Geochemical Society.

Hauri was known in the scientific community for his instrumentation expertise. This reputation for precision extended into his hobbies, which included designing and building custom guitars.

He is survived by his wife, Tracy, and three children: Kevin, Matthew, and Michaela, as well as his father, Larry Hauri, sister, Stacy Mariano, brother, Roger Hauri, and their families. 

Hauri requested that in lieu of flowers, donations be made in support of the Merle A. Tuve Fellowship fund, which supports visiting scientists for short working stays at the Department of Terrestrial Magnetism.  Please see if you would like to donate to this fund in memory of Erik.