"The most beautiful thing we can experience is the mysterious. It is the source of all true art and science. He to whom this emotion is a stranger, who can no longer pause to wonder and stand rapt in awe, is as good as dead: his eyes are closed."   Albert Einstein - Living Philosophies

I am a PhD candidate in Astronomy at the University of Nevada, Las Vegas (UNLV) working with the research group of Prof. Jason H. Steffen. I joined the program in Fall 2017. I research the formation and evolution of planets from their interiors to their dynamics through computational techniques. I am interested in incorporating astrophysics and geophysics into an integrated understanding of planetary systems.

I love sharing science with others whether through my teaching, talks, or through outreach. I founded and emcee Astronomy on Tap, Las Vegas which shares space-related research through a fun pub trivia event.

Prior to UNLV, I graduated from Northwestern University with a degree in Integrated Science, Physics and Astronomy, and Earth and Planetary Science.

Curriculum Vitae

David R. Rice C.V. pdf

Last Updated : 24 July 2020

Current Areas

Terrestrial Planet Interiors

with Jason H. Steffen at UNLV

Use these drop-downs to show a corresponding ternary created with MAGRATHEA:

Mass M_Earth

Surface Temp. K

Atm. Mass %

Discoveries such as Kepler-10b, LHS 1140b, the seven planets of the TRAPPIST-1 system, and Proxima Centauri b show that small rocky planets are now firmly within observational limits. The densities of these observed terrestrial planets allow for a range of interior compositions from Mercury-like to volatile rich. However, the interior structure of a differentiated planet is degenerate with the observed density. To explore this degeneracy, we have developed an interior solver named MAGRATHEA. MAGRATHEA features enhanced ease-of-use and customizeable equations of state which empower our collaboration with high-pressure physicists. Using our code and dynamical simulations which include mantle stripping, I propose to constrain the interior structure of exoplanets by their formation histories. Paper on the code planned for Winter 2020. I presented posters on this work at the Kepler & K2 Science Conv. V and Exoplanets III conference.

Planet Dynamics

with Jason H. Steffen at UNLV


Following upon Rice et al. 2018 (described below), I am continuing to research the stability times of exoplanet systems. I simulate planetary systems on Cherry-creek, UNLV's supercomputer cluster, across a wide range of orbital parameters to understand planet crossing times. We are just beginning to understand the mechanisms driving tightly-packed planetary systems to instability. Orbital resonances play a vital part in this analysis. I probe these simulations with Bayesian statistics to understand the heteroscedasticity of instability times.
Past Projects

Survival of Closely Packed Planetary Systems

with Jason H. Steffen and Fred Rasio at UNLV and CIERA, Northwestern University


Due to the chaotic nature of the N-body problem, planetary systems often experience collisions of planets. The dynamics of these collisions are essential to the formation of stable systems and the wide variety of exoplanetary systems that have been observed. We use Mercury6 to simulate thousands of systems with a given orbital separation to better understand the timescales of instability. Among other findings, we find that, although the time until two planets in a multi-planet system cross orbits is well-known, the time until a planet-planet collision is dependent on initial conditions. I published this work in Dec. 2018 — ADS.

Solar Wind Turbulence

with Craig DeForest at SwRI

Solar winds are known to be "gusty", but the cause of this variability has been a topic of debate. Using the heliospheric imaging (HI-1) camera on board NASA’s STEREO spacecraft, we observed an ensemble of compact features in comet tails as they became entrained in the solar wind. By tracking these test particles with PDL tools, we found a surprising regime of semi-confinement that we attribute to turbulent eddies in the solar wind. Our paper was published in ApJ with ADS listing here. NASA press release found here.

Interplanetary Mass Transfer

with Jason H. Steffen at CIERA

Ejecta from asteroidal collision events can often be transferred between planets in a system. This process could be significant in exoplanet systems such as Kepler-36, with an outer planet whose semi-major axis is only 11% greater than the inner planet. We created a HEALPix sphere of test particles around a planet in Mercury6 to study mass transfer in a variety of systems. We temporarily halted this project after preliminary studies to focus on our current project. Prof. Steffen later continued; ADS listing of his publication here.
Astronomy on Tap
Astronomy on Tap, Las Vegas (AoT) seeks to present astronomy and related sciences to our Las Vegas community through engaging and accessible events. Each event includes space trivia (with prizes!), presentations about the final frontier, and beer. All (21+) are welcomed, no prior knowledge needed!

Our team consists of astronomy researchers from the University of Nevada, Las Vegas. We research in a wide range of topics from planets to black holes. I, David, am the founder and current emcee of AoT, LV. We held our 5th event in February of 2020 and hold 3-4 events a year at the amazing craft brewery, Astronomy Aleworks.

To learn about events follow us on Facebook. We have an active community, and I post weekly trivia, space news, Las Vegas events, and all kinds of other educational and fun space-related content.
At UNLV, I teach two physics labs a semester in mechanics, E&M, or modern physics to both non-majors and physics undergraduates. We take diversity and teaching seriously at UNLV. I take every opportunity to share my knowledge and help others in my graduate career. You can watch me discuss Pluto with the CSN Planetarium here.

After my undergraduate, I spent the academic year of '16-'17 as a Tutoring Fellow for SAGA Innovations in Chicago. I provided high-dosage, personalized tutoring in math to at-risk high school students in an underachieving school. Read about the success of the program here. I still enjoy tutoring in physics, math, and astronomy; please visit my site if you or someone you know would like in-person or online help.

You can hire me for tutoring at: wyzant.com/Tutors/David-the-Tutor.

Personal Bio
"All you really need to know for the moment is that the universe is a lot more complicated than you might think, even if you start from a position of thinking it’s pretty damn complicated in the first place."
Douglas Adams - Mostly Harmless

Hi, thanks for visiting my page. I am from a small town outside of the suburbs of Des Moines, Iowa. Astronomy first became a part of my life when I saw Saturn's rings through a telescope on a Cub Scout outing. In middle school, I became obsessed as I checked Astronomy Picture of the Day (APOD) every morning.

Fast-forward; I attended Northwestern University in Evanston, Illinois and completed three majors: Integrated Science, Physics and Astronomy, and Earth and Planetary Science. The Integrated Science Program requires classes in everything from organic chemistry to computer programming. The program fostered my interest in interdisciplinary research. As an undergrad, I started research on exoplanets with Prof. Jason H. Steffen at Northwestern.

I am now researching, teaching, and learning at the University of Nevada, Las Vegas where I will pursue my PhD in Astronomy. We are building a unique research team that can track chemical composition from the stellar nebula to the interior of planets. Our larger collaboration includes high-pressure physicists, astrobiologists, and geologists.

Outside of astrophysics, I enjoy playing card/board games and exploring the city of Las Vegas. However, my favorite activities involve getting out of the city with my wife to enjoy the outdoors through camping, hiking, and–of course–stargazing.

Contact Info