Professor Sarah Stewart
(Courtesy of John D. & Catherine T. MacArthur Foundation)

Professor Sarah Stewart named MacArthur Fellow

Sarah Stewart, professor in the Department of Earth and Planetary Sciences, has been honored with a 2018 MacArthur Fellowship. She is the third MacArthur Fellow in the UC Davis College of Letters and Science and the second in the Department of Earth and Planetary Sciences.

Stewart studies how planets form, developing new ideas about the evolution of the Earth and other planets. Her newly-built Shockwave Compression Laboratory uses what are essentially mounted cannons to reproduce conditions reached during the violent collisions that form planets. The experiments fuel novel ideas into how the Earth and Moon formed, and help scientists better understand planets outside our solar system.

Planetary Collisions


Sometimes known as the “Genius Grants,” the MacArthur Fellowship is a $625,000 award to extraordinarily talented and creative individuals as an investment in their potential. 

“It’s fitting that this prestigious no-strings-attached award goes to Professor Stewart because her curiosity and ingenuity know no bounds,” said UC Davis Chancellor Gary S. May. “I am thrilled for recognition this brings to her and our university community as a whole.”

The fellowship is awarded over five years and is a personal grant that the recipient can use however they see fit. Stewart said that while she does not yet have a specific project in mind, she hopes to use the funds for something “new and different.”

“I want to use it to enable something exciting that I haven’t had a chance to do yet,” Stewart said.

How the Earth and Moon Formed

Recently, Stewart and colleagues developed a new theory of the origin of the Earth and Moon. Previous thinking held that the Moon was stripped out of the Earth when another planet-sized object struck the Earth a glancing blow. But there are discrepancies between this model and the observed composition of the Earth and Moon.

Stewart and graduate student Simon Lock proposed instead that the Earth and Moon formed from an entirely new kind of celestial object, a gigantic spinning donut of vaporized and molten rock that they call a synestia. They showed how a synestia could be created from a high-energy collision between two planet-sized objects with high angular momentum.

“We are so pleased that Sarah Stewart is among the small cohort of 2018 MacArthur ‘Genius Grant’ recipients,” said College of Letters and Science Dean Elizabeth Spiller. “Sarah’s creative and distinguished scholarship enlarges the boundaries of what is possible; we are honored that the award recognizes the kind of curiosity-driven research and impact at the heart of everything we do in the college.”

Stewart received an A.B. (1995) from Harvard University and a Ph.D. (2002) from the California Institute of Technology. She was a professor at Harvard University from 2003 to 2014 before joining the faculty at UC Davis.

Previous winners

Stewart is the third MacArthur Fellow on the UC Davis faculty. The others are Professor Leah Krubitzer, Department of Psychology and Center for Neuroscience and Geerat Vermeij, distinguished professor of paleobiology in the Department of Earth and Planetary Sciences, both in the College of Letters and Science. 

Alumnus José Quiñonez (B.A., Chicano/a Studies, ’94) was awarded a 2016 MacArthur Genius Grant for his innovative work in poverty alleviation. And alumna Uta Barth (B.A., studio art, ’82) was recognized in 2012 for her abstract photography.

Becky Oskin, content strategist in the College of Letters and Science. Adapted from a story by  Andy Fell, UC Davis News and Media Relations.

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