Rachel Fry

Thank you for your interest!

I am a community college student at College of DuPage in Glen Ellyn, Illinois with plans to pursue a degree in planetary science. During my time at College of DuPage I have been active in the Astronomy Club, where we seek to promote public interest in astronomy, astrophysics, and aerospace to both community college students and the general public through outreach events. I have also been involved in NASA's Community College Aerospace Scholars (NCAS) program and geologic field studies in the Saint Francois Mountain range in Missouri.

A love of and deep regard for space science had been a part of my life from an early age, with a father who took our family to the desert to watch meteor showers as far back as I can remember, and with a mother who once dreamed of being an astronaut. However, while my friends left for college following graduation from high school, I followed my brother's footsteps and joined the United States Navy. While military service afforded me invaluable experience and independence, my interest in science never abated, and my post-service academic path led me to discover my deep interest in planetary science and research.

This summer I worked with Dr. Daniel Horton and Howard Chen on the modeling of Earth-like planets around M-type dwarf stars in order to understand the effects of the M-dwarf stellar spectrum on the upper atmospheres of these exoplanets. While I had previously been exposed to the very basics of atmospheric science, most of my experience lay in geology and geophysics, so I was excited to have an opportunity to work in this field and gain experience in a new aspect of planetary science research.

Before moving on I would like to thank the National Science Foundation for funding this research experience, to thank Aaron, Cliff, and Newlin for building and guiding us through such a valuable program, to thank Dan and Howard for their mentorship, and to thank my fellow CIERA REU cohorts for their support and camaraderie.

Please feel free to contact me at fry[dot]rachel[at]gmail[dot]com or visit my LinkedIn

The Research

Our study uses a comprehensive 3-dimensional chemistry-climate model (WACCM-X) to study the effects of Proxima Centauri’s stellar emissions in the Extreme Ultraviolet and X-ray spectrum on the ionosphere of an Earth-like planet. The photon flux in the Extreme Ultraviolet (EUV) and X-ray wavelengths is two orders of magnitude greater on an exoplanet around Proxima Centauri than it is on Earth around the sun, and so changes in photochemistry, ionization, temperature, and a multitude of other variables are anticipated. We are running three simulations: Two with slightly different ranges of incident stellar flux (representing exoplanets around Proxima Centauri), and one baseline model representative of Earth. We will be able to show the differences in the concentration of various ions and neutral gas species throughout the atmosphere between each simulation.

Why Proxima Centauri?

Proxima Centauri, the closest star to our own sun, is an M-type dwarf star. M-dwarfs are the most abundant type of star in the Milky Way Galaxy – they’re also not very bright compared to other stars, making it easier to block the light from the star and observe the planets orbiting around it. More importantly, Proxima Centauri has been observed across the entire electromagnetic spectrum, and that stellar data can be applied to models such as ours.

The Relevance

Most exoplanet habitability potential has, so far, been based on the geophysical properties of the planet. This study instead uses the astrophysical data (the stellar emissions) and models the solar effects on the upper atmosphere of the planet. By knowing the composition of the upper atmosphere of a planet with an active biosphere, like the one in our study, we can begin to apply this data to future studies in both exoplanet habitability and observation potential.

The Data

While the simulations are still running, final analysis is still pending. However, a snapshot of the data taken while the simulation is still in-progress shows interesting differences in the concentration of various ions in the upper atmospheres of the baseline model (Earth around the sun) and the exoplanet around the M-dwarf.

Our preliminary comparisons of the ionospheres show that while some ion species show greater concentrations around Proxima Centauri, they show the same change in concentration as you move upward through the pressure gradient, while other species show less concentration or wildly different changes in concentration between the simulations.

I will be excited to share future results here.