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Earth & Planetary Science Laboratory

Department of Earth and Environmental Sciences
Department of Physics and Astronomy
University of Rochester



I am a planetary scientist and an assistant professor at the Department of Earth and Environmental Sciences (primary), Physics and Astronomy (secondary), Laboratory for Laser Energetics (secondary) at the University of Rochester.

We are studying origin and evolution of planets and moons in the solar system and beyond.


Miki Nakajima
Assistant Professor


Graduate Students


I use a shock physics code called iSALE (impact Simplified Arbitrary Lagrangian Eulerian) to computationally recreate the Sudbury basin crater. Understanding Sudbury's formation channel enhances our knowledge of geology as a result of catastrophic event which in turn constrains our current interpretation of Earth's formation. My goal is to progress from impact analysis and apply it to research in planetary crustal formation and evolution.


I conduct shock experiments at the Laboratory for Laser Energetics (LLE) on (Mg,Fe)O samples that I synthesize here at the University of Rochester. The purpose of these experiments is to determine the electrical conductivity of a Basal Magma Ocean (BMO) that may have existed early in Earth's history. With a conductivity greater than 10,000 S/m, the BMO would have been able to produce its own magnetic field, which has ramifications for magnetic history of Earth before the current geodynamo within the core started. This work can be extended to other rocky planets, including exoplanets, since we have access to TPa pressures using the OMEGA EP laser.

Postdoctoral Scholars


My research interests lie primarily in the formation and evolution of planetary interiors using experimental, numerical and analytical methods in fluid dynamics. My research is dealing with heat and chemical partitioning between metal and silicates during the formation of terrestrial planets. I mainly focus on mixing processes responsible for metal-silicate equilibration in early magma oceans, both during planetary impacts and in the following post-impact flow. I am also interested in the origin of the early Earth magnetic field, investigating in particular dynamo simulations in an early magma ocean.


I am a lunar scientist and volcanologist currently re-examining the Moon’s early bombardment history through mineral microtexture analysis, geochronology, analytical geochemistry, and shock experiments. I also investigate aspects of lunar magma ocean crystallization using high pressure-temperature experiments, phase equilibria and convection models, and machine learning.


My research area revolves around Celestial Mechanics. I study Hamiltonian systems, tidal dissipations and collisions. I am currently simulating the formation of the Moon from a collisional and fragmenting protolunar disk. To this aim, I developed the N-body software NcorpiON. Starting September 2024, I will be working on the orbital stability of exoplanets under tidal dissipation, in order to constrain the architecture of previously discovered exoplanetary systems from available observations. My website is available at


I am a planetary astrophysicist, broadly interested in planet formation and evolution. I study the effects of the giant impacts on planets using numerical simulations. I investigate how these collisions shape the planets' properties e.g., their interior, composition, satellite system or long-term evolution.


Soren Helhoski Undergraduate student, 2019--current
Scott Hull Graduate student (Ph.D.), 2019 -- 2024
Sarah Harter Graduate student (M.Sci.), 2021-- 2023
Ian Szumila  Postdoctoral Scholar, 2021-- 2023
Turi Useda  Highschool Student, Aug, 2022
Aidan Parris 
 Highschool Student, Aug, 2022
Angel Paz  Undergraduate student, 2021-- 2023
Natalie Allen Undergraduate student, 2020-- 2022
Arnav Sharma Undergraduate student, 2019- 2022
Jeremy Atkins Undergraduate student, 2018 -- 2021
Pham Nguyen Graduate student, 2019 -- 2020
Tyler Labree REU Summer student, 2019



Physics of Planetary Interiors (2019, 2020, 2022)  
Geodynamics (2019, 2021)
Designing your space mission (2020, 2021) 


moon formation

According to the canonical model, the proto-Earth was hit by a Mars-sized object approximately 4.5 billion years ago. The movie below shows entropy of the mantle (the extent of shock heating) in the red-yellow colors and iron core in grey. We developed a smoothed particle hydrodynamics (SPH) code from the ground up where a fluid is expressed as a collection of spherical particles.

Feel free to download the movie from here: [canonical - entropy] 

Please cite Nakajima and Stevenson (2014, 2015).

It may take a few seconds to load the movies ... please stay patient!

Canonical Moon-forming impact

Canonical Moon-forming impact

Canonical Moon-forming impact
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Canonical impact model

Canonical impact model

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A number of impact models have been suggested, including (1) canonical model, where the proto-Earth is hit by a Mars-sized impactor, (2) fast-spinning Earth model, where the rapidly rotating proto-Earth is hit by a small impactor, (3) half-Earths model, where two half-Earth objects collide, and (4) multiple impact model, where the Moon formed out of multiple small impacts.

We perform numerical simulations to represent (1)-(3) models as below. The green and yellow represent the mantle of the proto-Earth and impactor, whereas grey and white represent their iron cores, respectively.

Feel free to download the movie from here:

[canonical - material]  [fast-spinning Earth - material]  [half-Earths - material] 

Please cite Nakajima and Stevenson (2014, 2015).

Moon-forming impact models

Moon-forming impact models

Moon-forming impact models