Earth & Planetary Science Laboratory
Department of Earth and Environmental Sciences
Department of Physics and Astronomy
University of Rochester
Team
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
Associate 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.
I am interested in studying the evolution of planetary bodies through geochemical analysis of planetary samples–both synthetic and natural. A major focus of my research involves exploring the extent of ancient silica-rich crust production of the Moon. I use techniques such as X-ray Absorption Near Edge Structure spectroscopy (XANES) to examine lunar zircons, as well as materials synthesized in the lab. I also conduct dynamic compression experiments at the Laboratory for Laser Energetics to understand the structure and behavior of Fe-silicates at conditions found within the interior of a super-Earth exoplanet.
Postdoctoral Scholars
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.
I am a postdoctoral researcher primarily interested in the dynamics of planetary systems and moons. I have worked on how equatorial bulges from young stars' evolving spins can dramatically impact the dynamics of their planetary systems. The orbital precessions caused by these bulges reduce with time as the star slows its spin--this can bring precession rates of planets into and out of simple integer ratios with one another (resonances), which can transfer dramatic amounts of angular momentum between planets, potentially frustrating their stability or detectability. Currently I am interested in the dynamics of (exo)moon formation around low-mass planets like Earth and how distant moonlets interact and whether they merge. My website is listed here.
Alumni
Kim Cone Postdoctoral Scholar, 2022 -- 2024
Jérémy Couturier Postdoctoral Scholar, 2022 -- 2024
Victor Lherm Postdoctoral Scholar, 2021 -- 2024
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
Undergraduate Students
research
My goal is to build theoretical models to explain geochemical, geophysical, and astronomical observations. My research focuses on the formation and evolution of terrestrial planets. Click the images below for details!
classes
Physics of Planetary Interiors (2019, 2020, 2022)
Geodynamics (2019, 2021)
Designing your space mission (2020, 2021)
simulations
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).
The visualization was done by Roshan Mehta and the data is from Hull et al 2024.
Moon-forming impact models
Moon-forming impact models
Canonical impact (HR) (Roshan Mehta)
Canonical impact model
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]
Moon-forming impact models
Moon-forming impact models
Canonical impact (HR) (Roshan Mehta)
Canonical impact model
Fast-spinning Earth
selected publications
peer-reviewed
Green indicates contributions from the team members
Allen, N., Nakajima, M., Wuennemann, K., Helhoski, S., and Trail, D. Modeling the Vredefort Crater impact with iSALE. Submitted.
Canup, R., Righter, K., Dauphas, N., Pahlevan, K., Cuk, M., Lock, S. J., Stewart, S. T., Salmon, J., Rufu, R., Nakajima, M., Magna, T. Origin of the Moon, New Views of the Moon II. in press.
Nakajima, M., and Genda, H., Asphaug, E. I., and Ida, S. Large planets may not form fractionally large moons. Nature Communications, 2022, 13, 568 [Nature Communications].
Tarduno, J. A., Cottrell, R. D., Lawrence, K., Bono, R. K., Huang, W., Johnson, C. L., Blackman, E. G., Smirnov, A. V., Nakajima, M., Neal, C. R., Zhou, T., Ibanez-Mejia, M., Oda, H., and Crummins, B., 2021. Absence of a long-lived lunar paleomagnetosphere. Science Advances, 7, eabi7647. [Science Advances]
Nakajima, M., Golabek, G. J., Wuennemann, K., Rubie, D. C., Burger, C., Melosh, H. J., Jacobson, S. A., Manske, L., Hull, S. D. 2021. Scaling laws for the geometry of an impact-induced magma ocean. Earth and Planetary Science Letters, 568, 116983. [SienceDirect][arXiv]
Quillen, A. C., Zaidouni, F., Nakajima, M., Wright, E., 2021. Accretion of Ornamental Equatorial Ridges on Pan, Atlas and Daphnis. Icarus, 357, 114260. [Icarus]
Wright, E., Quillen, A. C., South, J., Nelson, R. C., Sánchez, P., Martini, L., Schwartz, S. R., Nakajima, M., Asphaug, E. 2020. Boulder stranding in ejecta launched by an impact generated seismic pulse. Icarus, 337, 113424. [ScienceDirect]
Quillen, A. C., Martini, L., and Nakajima, M., 2019. Near/far side asymmetry in the tidally heated Moon. Icarus, 329, 182-196. [ScienceDirect]
Nakajima, M., and Stevenson, D. J., 2018. Inefficient volatile loss from the Moon-forming disk: reconciling the giant impact hypothesis and a wet Moon. Earth and Planetary Science Letters, 478, 117-126. [ScienceDirect]
Jacobson, S. A., Rubie, D. C., Hernlund, J., Morbidellie, A., and Nakajima, M., 2017. Formation, Stratification and Mixing of the Cores of Earth and Venus. Earth and Planetary Science Letters, 474, 375-386. [ScienceDirect]
Hauri, E. H., Saal, A. E., Nakajima, M., Anand, M., Rutherford, M. J., Van Orman, J. A., and Le Voyer, M., 2017. Origin and Evolution of Water in the Moon's Interior. Annual Review of Earth and Planetary Sciences, 45, 89-111. [Annual Reviews]
Nakajima, M., and Ingersoll, A. P., 2016. Controlled boiling on Enceladus. 1. Model of the vapor-driven jets. Icarus, 272, 309-318. [ScienceDirect]
Ingersoll, A. P., and Nakajima, M., Controlled boiling on Enceladus. 2. Model of the liquid-filled cracks. Icarus, 272, 319-326. [ScienceDirect]
Nakajima, M., and Stevenson, D. J., 2015. Melting and Mixing States of the Earth’s Mantle after the Moon-Forming Impact, Earth and Planetary Science Letters, 427, 286-95.
Nakajima, M., Stevenson, D. J., 2014. Investigation of the Initial State of the Moon- Forming Disk: Bridging SPH Simulations and Hydrostatic Models. Icarus, 233, 259-267.
Nakajima, M., 2016. Core Science: Stratified by a Sunken Impactor. Nature Geoscience, News & Views, 9, 734-735. [Nature Geoscience]
Nakajima, M., and Stevenson, D. J. Dynamical mixing of planetary cores by giant impacts.
other publications
in preparation
contact
Email: mnakajima_at_rochester.edu
Phone: (585) 276-6617
Address: 227 Hutchison Hall, P.O. Box 270221
Rochester NY, 14627
