To Continue Being a Researcher
Misako Tatsuuma
(Research Scientist, iTHEMS)
What processes lead to the formation of planets? — Research Scientist Misako Tatsuuma aims to theoretically answer this question. Describing herself as "indecisive at times but fundamentally a perfectionist," Tatsuuma adds, "I consider strategies carefully before acting." This approach applies not only to her research but also to her private life. What are these strategies?
Keywords: Planet Formation Theory, Dust, Dust Aggregates, Material Strength, Work-Life Balance
Affiliation and position are as of the interview date: July 2024
(Written by Shino Suzuki (Photon Create Co., Ltd.) / Photo by Makoto Oikawa (Photographer))
Wanting to Live as a Researcher
This interview was conducted online. Misako Tatsuuma connected from her home. "The iTHEMS researcher recruitment guidelines clearly stated that remote work was possible. That one sentence was a decisive factor for me in applying," she said. To understand why, it is necessary to introduce Tatsuuma's journey up to this point.
Since elementary school, Tatsuuma had thought, "Physics is cool, I want to study physics." During her first year of university, she took a lecture on planet formation and thought, "This is fascinating! I want to do theoretical research," which led her to major in astronomy. She then went on to graduate school, where she began theoretical research on planet formation.
During her master's course, she took a year to study abroad [JA1] at the University of Copenhagen in Denmark. "Before fully diving into specialized research, I wanted to take a step back and carefully consider my future path," she explained. During her time abroad, she was surprised and inspired by the diverse ages and backgrounds of the people she encountered, including those who had returned to academia after working in the industry. After gaining experience through internships in the corporate sector, she ultimately decided to pursue a doctoral degree.
There were several reasons for this decision. First, she became fascinated with the simulations of dust particles in planet formation and wanted to continue this work. Another reason was that after getting married and seeing the life of her partner, also a researcher, she realized, "I want to live as a researcher too."
Giving Birth While in a Doctoral Program
Having decided to live as a researcher, Tatsuuma carefully planned her future life with her partner. Her partner is Akimasa Kataoka of the National Astronomical Observatory of Japan, with whom she also collaborates in research. "It was reassuring to have someone who understands the challenges of the research world support me. I also learned the importance of acting strategically."
The biggest dilemma was deciding when to have a child. After completing a Ph.D., many researchers become postdocs, working in positions with term limits of several years. Finding the right timing to have a child and take maternity leave during this period is not easy. "During the Ph.D. program, I was still a student, so there was no system for maternity or parental leave, but I could take a leave of absence. Furthermore, I learned that the National Astronomical Observatory of Japan, where my lab was located, had a childcare room where even graduate students could leave their children. Such a favorable environment might not be available as a postdoc. So, I decided to have children during my doctoral program!"
Tatsuuma gave birth to two children while in the Ph.D. program. Reflecting on that time, she says, "While my peers were steadily progressing in their research, I was suffering from severe morning sickness, and my research activities were stalling during pregnancy. I was anxious and frustrated, but I had to do what I could to the best of my ability."
Despite these challenges, she found time to advance her research and completed her doctoral dissertation, "Material Strength of Dust Aggregates in Planet Formation." The building blocks of planets are dust (solid particles) about 0.1 µm in size drifting in space. Dust particles grow by adhering to each other through intermolecular forces. Tatsuuma's research aimed to simulate and model the material strengths of dust aggregates when pulled or compressed and to clarify the process by which dust aggregates grow into kilometer-sized planetesimals by comparing their strengths to those of comets and asteroids. Planetesimals grow through repeated collisions and coalescence, eventually giving rise to planets. Comets and asteroids are thought to be the remnants of planetesimals that did not become planets, and their material strengths have been studied through explorations.
Her doctoral dissertation was awarded the School of Science Research Encouragement Award at the University of Tokyo and an honorable mention in the International Astronomical Union (IAU) Ph.D. Prizes. "My research is not mainstream but tackles niche areas. I am confident that my perspective on the material strengths of dust aggregates is crucial for understanding planet formation, but I thought it might be difficult to receive recognition. I was delighted that my research was acknowledged," Tatsuuma says with a smile.
Casting a Wide Net Among Diverse Theoretical Researchers
Tatsuuma completed her Ph.D. in four years, taking half a year off for each of her two births. After working as a JSPS Research Fellow at Tokyo Institute of Technology, she joined iTHEMS in October 2023. "Actually, planet formation theory is currently facing a re-evaluation. In iTHEMS, which offers the best environment for theoretical researchers, I hope to clarify the planet formation process from my unique perspective on the material strengths of dust aggregates," she says with determination.
In recent decades, numerous protoplanetary disks, where planets are forming, have been observed outside the solar system, providing data on dust aggregates. This data suggests that 0.1 µm-sized dust particles gather to form dense mm-sized dust aggregates, which then accumulate to create larger aggregates.
"It is now thought that dust aggregates are hierarchical. The dense mm-sized dust aggregates are called 'pebbles.' My goal is to first understand how pebbles form, and then simulate and model the material strengths and behavior of pebble aggregates. I believe that planetesimals can be explained by pebble aggregates, and with this approach, I may be able to propose a new theory of planet formation," Tatsuuma projects.
Having been at iTHEMS for a year, Tatsuuma shares that "iTHEMS is full of theoretical researchers from diverse fields, and every time I participate in coffee meetings, I discover new perspectives. Right now, I'm casting a wide net, gathering information and knowledge, thinking, 'This method might be useful someday.'"
A Message to Everyone Around
"At iTHEMS, each person's research style is highly respected, and I am very grateful for that," Tatsuuma says. "Theoretical research can be done anywhere as long as you have a computer. I utilize remote work a lot. My children are still young, so I'm always pressed for time, but with remote work, I can use commuting time for research and respond quickly when my children are ill. Without the option of remote work, I might have had to put my research on hold until my children were older."
Tatsuuma gave birth to her second child during the COVID-19 pandemic. At that time, conferences and workshops were held online. "In the past, if you couldn't attend in person, you had to give up participating. Thanks to the option of online participation, I was able to attend conferences and workshops without having to travel with my child, which was a great help. Although it seems that fewer conferences and workshops are now offering online participation, I hope that option remains available."
Tatsuuma frequently shares her experiences and challenges related to pregnancy, childbirth, and childcare whenever possible [1]. "Because these issues are not visible, it's essential to communicate them properly not only to those directly involved but also to others around them. By first raising awareness and fostering understanding, I believe more people will be able to continue their research without having to give it up due to childcare or other reasons," she says softly but firmly.
On the other hand, she murmurs, "I still worry about whether I can survive as a researcher." She continues, "Publishing impactful papers frequently is also a strategy for surviving as a researcher. But it doesn't suit me. I aim to conduct research that is not flashy but important, based on my unique perspective, and to expand my research opportunities by gaining educational experience. With this strategy, I hope to continue surviving as a researcher."