Sarah Stewart’s research group investigates the formation and evolution of planetary bodies. Our primary techniques are shock wave experiments to measure material properties and numerical simulations of planetary processes. We tackle a broad range of problems in planetary science by focusing on understanding the feedbacks between physical processes and changes in material properties.

Where did the Moon come from? A new theory.

Giant Impacts Shake Up the Internal Pressures of Planets

In a new paper, published in Science Advances, Simon Lock and I show that the internal pressures can vary wildly during the giant impact stage of planet formation. The fast spin rates generated by a giant impact can lower the internal pressure by 10’s of gigapascal (100’s kilobars). The change in pressure affects the chemistry of the core and mantle and can explain some of the puzzling observations about the abundance of moderately siderophile elements in Earth’s mantle.

More information about this work at Simon Lock’s web site.

Planetary Collisions Can Drop the Internal Pressures in Planets, Caltech.

Pressures and shape of the Earth during the tidal evolution of the Moon

Calculation of the pressure changes in Earth’s mantle during the tidal evolution of the Moon.

Colored contours of pressure in a slice through the planet perpendicular to the spin axis.

Video credit: Simon Lock, Caltech


September 2018: We are pleased to announce the launch of CLEVER Planets (the Cycling of Life-Essential Volatile Elements on Rocky Planets), a NASA NExSS team investigating the necessary chemistry for a rocky planet to host life.

UC Davis announcement: How Do you Make an Earth-Like Planet?

Simons Collaboration on the Origin of Life

Image credit: NASA / Jenny Mottar

Sarah Stewart is a new Investigator in the Simons Collaboration on the Origins of Life. Her work will examine the effects of impact cratering on the environment of the early Earth.

DOE Center for Matter at Extreme Conditions

Image credit: National Ignition Facility at Lawrence Livermore National Laboratory

Sarah Stewart is a Co-PI on the new DOE-NNSA Center for Matter at Extreme Conditions. She will use shock physics experiments to study the physical properties and equations of state of planetary minerals and gases at extreme pressures and temperatures. These data will be used to understand the interior structures of planets and the outcomes of planetary collisions. The Center is led by Professor Farhat Beg at U. California San Diego.

Stewart Group Videos

Pressure changes in Earth as the Moon's orbit increases Shock Compression Lab Where did the Moon come from? A new theory | Sarah T. Stewart Making a Synestia 40-mm gun rebound Moon Formation Simulation Moon Forming In a Cooling Synestia Grand Tack with Fragmentation (f2 aeiGT) Grand Tack with Fragmentation  (f7a acfGT) A Potential Moon-Forming Impact Event An Unsuccessful Moon-Forming Giant Impact High Angular Momentum Giant Impact for Lunar Origin Tidal Evolution of the Moon through the Evection Resonance Tidal Evolution of the Moon through the Evection Resonance 2 Mercury Giant Impact Merging Collisions between Ice/Rock Planets Hit-and-Run Giant Impact Catastrophic Disruption of a Water/Rock Planet Hit-and-Run Impact between Water/Ice Bodies Haumea Graze-and-Merge Giant Impact Impact Origin of the Haumea System South Pole Aitken Basin-Forming Impact on the Moon Chicxulub Crater Formation Cratering in Ice: Figure 2a Cratering in Ice: Figure 2b Cratering in Ice: Figure 7a Cratering in Ice: Figure 7b Cratering in Ice: Figure 8a Cratering in Ice: Figure 8b NASA Boiling Fluids Behave Quite Differently in Space Canonical Moon Forming Impact Proposed Moon Forming Impact

Stewart Group News

Phil Carter’s work on the cover of JGR-Planets

February 21st, 2020|Comments Off on Phil Carter’s work on the cover of JGR-Planets

Our paper on the energy budget of giant impacts is on the cover and all over the word cloud for the issue: Read more: The energy budgets of giant impacts Carter, P. J., S. J. [...]

Come join the parade…..

December 4th, 2018|Comments Off on Come join the parade…..

Sarah will be the Grand Marshal for the 105th Picnic Day at UC Davis. Adventure Awaits!

MacArthur Fellowship

November 7th, 2018|Comments Off on MacArthur Fellowship

The Stewart Group celebrating Sarah's MacArthur Fellowship.  

Space Unites the World

October 4th, 2018|Comments Off on Space Unites the World

Some thoughts on the theme of World Space Week. I love this graphic by Photon Illustration.  

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