Dr. Amirhossein Bagheri

Introduction

I am currently a researcher in the group of Prof. Mark Simons in the Division of Geological and Planetary Science at the California Institute of Technology with close collaborations with NASA Jet Propulsion Laboratory in the beautiful city of Pasadena. As an space and math enthusiast, and, by training, a planetary geophysicist, I have a broad interest in studying the interior and evolution of various planets and moons in our Solar System using geophysical methods, specially in connection to space missions. The ultimate goal is understanding the origin and present-day interior properties of the planets and moons, particularly their habitability. In my current role at Caltech, I mainly work on modeling the interior structure and the geodetic observables of Saturn's spectacular moon, Enceladus, and Jupiter's fascinating moons, Europa, Io, and Ganymede, as well as Mars and its two mysterious moons, Phobos and Deimos.

Before joining Caltech, I obtained my PhD in planetary geophysics followed by being a postdoctoral researcher at ETH Zurich, Switzerland, one of the world's leading universities in Earth and planetary sciences. My PhD in Zurich was defined in the context of NASA's Mars InSight mission, a discovery class mission which put the first successfull seismometer on the surface of the red planet. Specifically, I studied the interior of Mars and its moons Phobos and Deimos, mainly exploiting their gravitational response known as solid body tides. I also worked on modeling the evolution of Martian moons with the aim to decipher their history and origin. Next, I continued by working on the tidal and thermal evolution of icy/ocean worlds such as Pluto and Charon, with the purpose of understanding the properties of their subsurface oceans.

Surprisingly enough, I had obtained yet another PhD from the University of Tehran in Iran, following a Masters degree, both in Civil Engineering where my thesis had a large geophysical overlap. I obtained my Bachelors in Civil Engineering from Sharif University of Technology in Tehran.

Alongside my research, in my free times I enjoy photography, traveling, playing and watching soccer, swimming, listening to music, hiking, and reading poems. If you are interested, join me in this fabulous journey...

Research

Research interests

Given the interdisciplinary nature of planetary science, I am interested in various topics in this realm, particularly those hinged to geophysics. I try to treat the planetary science questions in a practical and objective way! As a result, I compile a suite of skills and approaches, including numerical methods, inversion techniques, orbital dynamics, thermodynamic calculations, and solid-state mechanics, for various problems of interest in planetary science, ultimately aiming to understand the interior properties, origin, evolution, and habitability of planets and moons in Solar system.

My primary areas of interest are Mars and its moons Phobos and Deimos, Enceladus, Europa, Pluto, and Charon. But I am always curious to explore other bodies as well!

More specifically, I am currently interested in following areas in planetary geophysics:

Probabilistic inverse problems

Below is a very brief description of my current and past projects. More details will be provided soon!

Current projects

I am currently working on several projects with regard to Enceladus, Galilean moons, Mars and its moons, and theoretical aspects of orbital dynamics. Stay tuned for updates!

Completed projects

Mars

I have worked on various problems in planetary geophysics field. This include modeling the interior of Mars based on self-consistent thermodynamics approach and several viscoelastic models to compute the tidal response. I use this is an inverse problem approach using Markov Chain Monte Carlo sampling to constrain the interior properties of Mars. This study provided pre-mission insights into the main interior structure elements of Mars including the size of its layers, and the viscoelastic properties of the mantle. I also predicted attenuation within Mars across a long range of periods from the seismic waves over normal modes, tides, and long period planetary wobbles.

Phobos and Deimos

I worked on the tidal-orbital evolution of the Martian moons, Phobos and Deimos with the aim of studying their history, origin, and the interior structure. I used the constraints obtained by studying the seismic waves and tides on Mars's interior structure to predict the dissipation properties during the orbital evolution of Phobos and Deimos. For this study, I developed a rigorous tidal-orbital evolution model which incorporates high order eccentricity functions and tidal dissipation due to the libration in longitude of the moon. This study resulted in a new hypothesis about the origin of the moons as being fragments of a common progenitor which was disintegrated around 1-2.7 billion years ago.

Icy-ocean worlds

In this project, I extended my orbital evolution model for the case where the spin and orbital rates of none of the two bodies are synchronised. I combined this model with a thermal evolution model appropriate for icy bodies which takes into account, in addition to the radiogenic heating, the heat generated as result of tidal dissipation. I used this methodology to study the coupled thermal and orbital evolution of the Pluto and Charon system with the aim of constraining the properties of the their subsurface liquid oceans.

Seismic waves in complex media

I have worked on theoretical aspect of seismic wave propagation in media consisting of anisotrpic solid material and fluids, using semi-analytical methods, with the aim of understanding the effect of anisotropy on wave propagation and their interaction with the fluid layers.

Collaborators and advisors

Publications

Do not hesitate to write me with a request for copy of the papers, if you do not have access to them.

Selected Journal articles

Personal

To be completed soon...

Contact

Interested in reaching out?

Send an email to one of the addresses below:

Outreach

From time to time, I participate in various outreach activities to disseminate scientific news within the planetary science community to a broader audience!

Elements

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    print 'Iteration ' + i;
    deck.shuffle();
    i++;
}

print 'It took ' + i + ' iterations to sort the deck.';