Dr. Reetika Joshi

Did you always know that you wanted to study Physics?

In one word: Yes. My father is a science teacher, and he began teaching me from a very young age. Growing up with his innovative and engaging style of teaching, science quickly became my favorite subject. That early inspiration stayed with me, and over time, with the best Science teachers (mainly the Physics teachers in my high school and later in the university) my interest deepened — ultimately leading me to pursue a Ph.D. in Physics, with a specialization in Solar Physics. I now make it a priority to engage in public outreach whenever I get the opportunity, sharing scientific concepts in simple, relatable language.

Photo Credit: Reetika Joshi.

What science questions do you investigate?

I study the fine-scale structure and dynamics of solar flares, which is among the most energetic phenomena associated with solar activity. These events, often originated from active regions, or more commonly known as sunspots, impact Earth's communication systems, satellites, power grids, and generate auroras. These events result from the rapid release of magnetic energy in the solar atmosphere and are observable across the entire electromagnetic spectrum, from radio waves to X-rays and gamma rays. A common signature of flares is the appearance of elongated, bright features known as flare ribbons, which mark the chromospheric footprints of energy deposition by accelerated particles during magnetic reconnection. The detailed morphology of these ribbons provides critical diagnostics for understanding the spatiotemporal evolution of the reconnection process. My current research focuses on analyzing flare ribbons and comparing their spectroscopic characteristics with results from RADYN simulations to infer the rate of energy deposition into the lower solar atmosphere. Ultimately, our goal is to probe the formation and dynamics of flare ribbons and gain deeper insight into the underlying physical mechanisms by comparing observational data with magnetohydrodynamic (MHD) models.

Photo Credit: Reetika Joshi.

How did you end up working at NASA Goddard?

After completing my Ph.D. in India, I joined the University of Oslo as a postdoctoral researcher in 2022. During this time, I became actively involved in observational campaigns using the Swedish 1-m Solar Telescope (SST) located in the Canary Islands, Spain. Over the past three years in Oslo, I participated in four observing campaigns at the SST and collected a significant number of solar flare datasets, many of which were coordinated with space-based observations from NASA's Interface Region Imaging Spectrograph (IRIS) telescope. My research has primarily focused on solar flares, and I have closely followed the work of the group at NASA Goddard Space Flight Center (GSFC), led by Dr. Joel Allred, who are experts in modeling the atmospheric response to flares from the photosphere through the chromosphere and transition region, up into the corona. I found that my observational background aligns well with the theoretical expertise at GSFC, complementing each other well. The opportunity to interact with several prominent scientists at Goddard has greatly inspired me to pursue my early research career here, and I am thoroughly enjoying the experience so far.

What is one of your favorite moments in your career so far?

Throughout my research journey, I have found great fulfillment in working closely with international collaborators, exchanging ideas and building partnerships across institutions and cultures. Among the many rewarding experiences, one that holds special significance for me is receiving the Best Ph.D. Prize in 2022 from the International Astronomical Union (IAU). This recognition, awarded during the IAU General Assembly in Busan, South Korea, was not only an honor, but also a deeply motivating moment. It reinforced my commitment to pursuing high-quality, impactful research and affirmed the value of my contributions to the solar physics community.

What was your first big research achievement?

In the final year of my Ph.D. in 2020, I was awarded the Raman-Charpak Fellowship under the Indo-French scientific collaboration program — a significant achievement in my academic journey. This opportunity allowed me to conduct part of my doctoral research at the Observatoire de Paris, in Meudon, France, where I had the privilege of working with a distinguished group of solar physicists. The experience greatly broadened my scientific perspective and deepened my understanding of solar phenomena. It was both intellectually enriching and personally rewarding, and I continue to maintain a strong research collaboration with the group to this day.

What science question intrigues you the most?

I am particularly intrigued by the process of “magnetic reconnection”. Magnetic reconnection is a fundamental plasma process that transforms magnetic energy into plasma energy, which leads to accelerate and heat the plasma. Although it has been studied extensively over the past few decades and the solar physics community has come a long way with different models and observations to explain the solar eruptions with the crucial role of magnetic reconnection in solar eruptions, it still remains an open and evolving question in solar physics. With the advent of state-of-the-art observations and advanced simulations, scientists continue to uncover new complexities in how magnetic energy is rapidly converted into heat and kinetic energy. Understanding this process in greater detail is crucial to unraveling many fundamental mysteries of solar activity, such as solar flares and coronal mass ejections. We look forward to new observations from ongoing and upcoming NASA missions, including IRIS, DKIST, and MUSE.

Photo Credit: Reetika Joshi.

What do you like to do in your free time?

Outside of my academic work, I'm an avid cricket fan — a sport I'm often asked to clarify as different from baseball! While living in Oslo, I joined a Norwegian cricket club and actively played with them. I really miss that experience now, as I haven't yet found a club or opportunity to continue playing here. In Oslo's cold climate, we played indoors for most of the year, but during the summer, we had outdoor matches, which I particularly enjoyed. I also love watching cricket and closely follow major championships whenever they're underway.

Apart from sports, I enjoy cooking in my free time. I cook different Indian cuisines and love exploring different cuisines and trying out new recipes. Cooking often goes hand-in-hand with another passion of mine — music. Old classical Bollywood songs are a big part of my life, and I especially enjoy listening to them while I cook. I also have a deep appreciation for the folk music of my native region, Kumaun in Uttarakhand, and I enjoy both listening to and singing these traditional songs. Music, in all its forms, continues to be a meaningful and joyful part of my life.

Photo Credit: Reetika Joshi.