Reaching for the Stars
Indian American astrophysicist Madhulika Guhathakurta talks about her interest in astrophysics and her incredible body of work at NASA.
On August 21, 2017, all of North America was treated to a total eclipse of the Sun. It was dubbed “The Great American Eclipse” by the media, as the last time the contiguous United States saw a total eclipse was in 1979. NASA’s lead scientist for the 2017 eclipse was astrophysicist Madhulika Guhathakurta.
Born in Kolkata and educated in Mumbai, New Delhi and Colorado, Guhathakurta holds a master’s degree in astrophysics from the University of Delhi and a Ph.D. from the University of Denver. She led the Living With a Star program at NASA for 15 years, which focuses on understanding and ultimately predicting solar variability and its diverse effects on Earth, human technology and astronauts in space.
The program gave rise to another initiative, known as the International Living With a Star, which brings together all the space agencies of the world to contribute toward the scientific goal of understanding space weather. Guhathakurta served as the chair of this group for four years and remains a member of its steering committee.
She has been a program scientist for Solar TErrestrial RElations Observatory (STEREO), Solar Dynamics Observatory (SDO), Van Allen Probes, Solar Orbiter, Parker Solar Probe and other missions. Guhathakurta is a spokesperson for NASA’s Heliophysics Division and has created graduate textbooks on this new discipline, which is a hybrid of astrophysics and meteorology. Her research has focused on the study of the Sun as a star, its influence on Earth, and Sun’s outermost layer, the corona.
Excerpts from an interview.
Could you please tell us about your background—growing up in India, your early interest in science and your education at the University of Delhi?
When I was very young, about 7 years old, in Kolkata, I used to watch the night sky. As I looked at the stars, I had the same question that NASA puts in big labels as one of its quintessential problems: “Where did we come from?” Even in those early years, I’d drive my father up the wall asking this. As an adult, I know how difficult it is to answer this question. You just can’t say “Big Bang” because the question remains, well, what was there before the Big Bang? But I never gave up the quest.
It was in Delhi where I first started my serious pursuit of physics or astrophysics. I finished my higher secondary in science and joined Hindu College to pursue a Bachelor of Science degree in physics and, then, joined Delhi University to pursue my master’s degree in astrophysics and general theory of relativity.
After you moved to the United States to pursue your Ph.D., you focused your research on the study of the Sun. How did you get interested in this?
In graduate school, I chose to study the Sun, the only star we can study in great detail. My personal research has been directed toward the synthesis of a number of multi-wavelength observations, ranging from radio to extreme ultraviolet and, in situ, for purposes of characterizing the source regions of solar wind and coronal mass ejections and their propagation through the interplanetary medium. Energetic particles associated with these coronal mass ejections and solar wind cause space weather on Earth and other planets. This has direct consequences here on Earth and on society at large—the very theme of NASA’s Living With a Star program.
In fact, it was during my graduate schoolwork when I was dreaming of this mission called “Solar Probe” to send a spacecraft to within few solar radii of the sun to verify some of the most hotly-debated topics in solar physics. Little did I know that someday, I would be a champion for making this mission real. As a research scientist, I have been a co-investigator on five Spartan 201 missions to study the solar corona in white-light and UV [ultraviolet] radiation and eight eclipse expeditions from ground.
In 1998, you joined NASA. What opportunities did the position provide you? Please tell us about some of the fascinating projects that you have been involved with.
As a NASA astrophysicist, I have had the opportunity to work as a scientist, mission designer, instrument builder, director and manager of science programs, and teacher and spokesperson for NASA’s mission and vision in the Heliophysics Division. Occasionally, I perform all of these roles in a single day.
At NASA, we are privileged to see and to know so many things that ordinary people don’t get a chance to experience; for example, some of our imagery! I came up with a storyline to share the Living With a Star program and show some of these exquisite images. I helped in the creation of two major planetarium shows, “Cosmic Collisions” and “Journey to the Stars,” in partnership with the American Museum of Natural History in New York and the National Air and Space Museum in Washington, D.C. I also helped in the production of a 3D IMAX and planetarium show featuring the STEREO mission, “3D Sun.” These shows are running all over the world. Children, general public, older people, are all learning something about the cosmos that they had no way of knowing otherwise. So, these are some of the excitements, I would say. And, just recently, I was the lead program scientist for the August 21, 2017, total eclipse across America.
Please tell us about the Living With a Star program.
Living With a Star (LWS) was formulated and funded by the U.S. Congress as a new initiative in 2000. This program is quite unique in that its plan consists of flight missions, supporting targeted research and technology, and small space environment test-beds, orbital laboratories for new LWS concepts, all with the objective of providing science with societal impact. I became the first program scientist in 2001, through 2016. Presently, I am serving a detail at NASA Ames Research Center in Silicon Valley.
The program is highly interdisciplinary, involving domains of study stretching across [150 million kilometers], the distance between Sun and Earth, and varying in scale from the size of atoms to the size of stars. Some of the science goals have direct societal implications: to understand the variability of cosmic rays and solar energetic particles, which is crucial information for astronauts; to understand the Sun-climate connection—how solar electromagnetic radiation and particles influence the thermosphere, mesosphere, upper atmosphere and terrestrial climate; to forecast conditions in Earth’s radiation belts, where spacecraft routinely travel; and to understand the impact of SWx [space weather] on Earth’s upper atmosphere, crucial for satellite safety and terrestrial navigation, such as GPS [Global Positioning System].
We now have four spacecraft in various stages of planning, construction and actual flight. We launched the Solar Dynamics Observatory in February 2010 and Van Allen Probes were launched in 2012. We have started work on Solar Probe Plus, which will launch in 2018. Solar Probe Plus supersedes the Solar Sentinels, which are no longer necessary, thanks to another Heliophysics mission I am involved in—the twin STEREO probes. Finally, we have joined forces with the European Space Agency to equip and launch a Solar Orbiter, which will monitor solar activity from above the Sun’s equator.
In 2018, you will be leading a team for a historic Parker Solar Probe mission of NASA. Could you tell us more about it?
Parker Solar Probe is a historic mission to answer some of the fundamental mysteries of physics: Why is our star’s atmosphere thousands of times hotter than its surface? And what propels the solar wind that affects Earth and our solar system. We have been wrestling with these questions for decades, and this mission should finally provide the answers.
I have been thinking of this mission since 1983, even as a graduate student, working on theoretical concepts on the physical properties of the corona and fast solar wind and its extension into the heliosphere. In 2001, as I assumed the responsibility of the LWS program, I also acquired the program scientist role for this mission. Since then, it took a long time and many studies to get Parker Solar Probe to a point where it was technologically achievable and financially viable. And, as its program scientist, I remained steadfast in my resolution to make this mission happen. In 2010, NASA selected the instrument payload for this mission, and it is expected to launch in July 2018. Quite incredible when I think of my childhood, when I just marveled at the stars, to actually sending the first spacecraft to a star.
Other than your work with NASA, have you been academically involved with astrophysics?
For the past 11 years, I have worked with the University Corporation for Atmospheric Research to develop five “Heliophysics” textbooks, summer school curricula, and training for the next generation of interdisciplinary scientists.
The program provides a special opportunity to students and undergraduate faculty to learn about heliophysics as a broad, coherent discipline that reaches, in space, from the Earth’s troposphere to the depths of the Sun and, in time, from the formation of the solar system to the distant future.
At the same time, a goal of the summer school is to provide a professional development opportunity to undergraduate faculty to incorporate heliophysics and astrophysics examples into physics, astronomy and earth science courses.
The fourth volume of the “Heliophysics” series—“Active Stars, their Astrospheres, and Impacts on Planetary Environments”—implicitly makes the case for a new research discipline: comparative heliophysics. As humans and their robots spread throughout the solar system, we will need this kind of interdisciplinary approach to understand the places we visit and to anticipate the dangers. What is the weather like on Titan today? How will a solar storm affect the ices of Europe? Is it safe to land on that comet?
What are some of your future plans at NASA and beyond?
I have drawn together the “disparate” strands of solar-terrestrial physics and enabled international cooperation with the ultimate goal of understanding the meteorology of space or space weather. A mission close to my heart, Solar Probe Plus, is planned for launch in 2018. It will even “touch the sun,” contributing to better characterizing and forecasting the radiation environment in which future space explorers will work and live. As such, I hope that all these efforts will help the human species go from being Earth-dwellers to space farers.
Natasa Milas is a freelance writer based in New York City.