About ASJ

Shigeru IDA
（Tokyo Institute of Technology　　　
　　　　　currently Institute of Science Tokyo）　　
　　　　　　　　　　　　　　　　　　　June 2023

I am pleased to announce that I have been elected to serve as the 52nd president of the Astronomical Society of Japan. Somehow, I have also been elected to a second term as Vice President of the Society for the Study of the Origin and Evolution of Life. From the nineteenth to the early twentieth centuryーuntil the debate about the possibility of canals on Marsーdiscussing the possibility of life on the various bodies in our solar system was a key issue in astronomy. Such discussions were revived with the first discovery of an exoplanet in 1995 and have accelerated since the 2010s with numerous identifications of super-Earths and other rocky bodies in the habitable zone of their stars. Add to that the 2005 discovery of a geyser on Saturn's moon Enceladus, which led to a rapid revival of astrobiology and a coming-together of astronomy and the life sciences. I suspect that may have something to do with my dual roles.

Mary Voytek, a director at NASA headquarters and a principal investigator at Tokyo Tech's Earth-Life Science Institute, told me that a major obstacle to promoting astrobiology in the United States is the separation between astronomers and planetary scientists. Planetary science has thus diverged from astronomy even more than it has from the life sciences. I have also heard from multiple researchers that the situation in Europe is similar. I served as president of the Japanese Society for Planetary Sciences, and considering the many members affiliated with both that organization and the Astronomical Society of Japan, I do not believe such a divergence presently exists here. Although there are certainly obstacles due to studies of the origins of life remaining outside the mainstream of the life sciences, barriers between astronomy and the life sciences seem much lower here compared with I have heard about in the West. I believe this deepness is characteristic of Japanese astronomy.

The field of astronomy is vast. The overlap between astronomy and the planetary and life sciences is just one example that reflects my transition in personal interests. If you will permit me a moment of personal reflection, as a high school student who had not yet decided what to study at university, the film 2001: A Space Odyssey left an indelible impression on me when I skipped class to go see it alone at a movie theater in Ginza, as did Sakyo Komatsu's science fiction novel At the End of the Endless Stream. To quote from that novel's Wikipedia page: "An hourglass is for some reason discovered in a Mesozoic stratum. Moreover, the sand within this hourglass never stops flowing. Kozo Nonomura, an assistant professor at the Institute for Theoretical Physics, and Professor Banjoya set off for a burial mound at the foot of Mount Katsuragi where the hourglass was found... Thus begins a story that transcends time and space." That book convinced me that I, too, wanted to embark on a journey that would transcend time and space.

First becoming fascinated with the then-emerging field of particle cosmology, I entered the Faculty of Science at Kyoto University. However, I was not accepted into a graduate school laboratory for particle cosmology, so after one more year struggle with applying several schools, I ended up in what is now called the Department of Earth & Planetary Science at the University of Tokyo. In the field of geophysics, using enormous amounts of data to dig deeply into the natural phenomena that occur around us as well as what we find pursuing the laws behind those phenomena is regarded as armchair philosophy. So, as a convert from theoretical physics, I experienced culture shock. But my venture into geophysics became the starting point for an exciting journey that later led me to astrobiology and even to theories on the origins of life.

After that, I became involved in the GRAPE project at the University of Tokyo College of Arts and Sciences, and later I transferred to the newly established Department of Earth and Planetary Sciences at the Tokyo Institute of Technology. Taking a one-and-a-half-year sabbatical starting in mid-September 1995, I first headed to the University of California, Santa Cruz (UCSC).

In early October, shortly after I arrived in the United States, The discovery of the first exoplanetーa so-called "hot Jupiter" was suddenly announced. The resulting explosion of new observations launched an era of excitement that felt like a gold rush. The UCSC Lick Observatory became one of Mecca for exoplanet observations, and as a theoretical researcher, I too was swept along with the torrent and found myself immersed in exoplanet system research. What was surprising was that within a year after that first discovery of a hot Jupiter, Earth-like exoplanets were being hotly discussed in the United States, with terms like "astrobiology" and "bioastronomy" being bandied about. It was like a dam behind which academic discussions of extraterrestrial life had been building up had suddenly burst.

In 1996, an announcement regarding possible evidence of life in ancient Mars found in a Martian meteorite was made with President Clinton in attendance. Subsequently, NASA established its Astrobiology Institute in 1998, and the geyser on Enceladus was discovered in 2005. Amidst all that, I unintentionally started drifting toward studying "life." In 2009, Tokyo Tech and the University of Tokyo started the GCOE program "From the Earth to Earths," with the somewhat grandiose theme of the possibility of life on Earth-like planets outside our solar system. The program also included advancing genome analysis technologies extended to analyses of extremophiles, microorganisms living in extreme environments. The same year, a six-year series of groups entitled "Study Group on Life in the Universe" and "Study Group on the Integration of Planetary Science and Life Science" began under the leadership of Norio Kaifu. In each meeting, ten to twenty researchers from fields such as astronomy, planetary science, geology, biochemistry, and biology gathered for intensive discussions, providing not only knowledge but also a sense of ongoing progress in each field.

Tokyo Tech's Earth-Life Science Institute (ELSI), a WPI program selected in 2012, boldly adopted the theme "The Earth and the Origin of Life, and Life in the Universe" for the continuation and development of the GCOE. Although studying the origin of life remained heresy in the life sciences, study groups focused on life's origins kickstarted things by enrolling members from various fields. They were all novices here, so it didn't matter whether they were young researchers or established professors. This resulted in somewhat fumbling but highly stimulating study groups. To turn all this into research that could be written up in papers, however, I needed some weapon that was unique to me as well as a novel approach to this new field I was entering. In my case, the direction of my researchーsimulating of synthesis of complex organic matter in spaceーdid not become clear until seven or eight years after the ELSI started.

I have thus gone wherever the currents were carrying me at the moment, pursuing whatever seemed interesting as it arose before me, from cosmology to geophysics, on to the solar system and beyond to exoplanets, encountering topics such as astrobiology and theories on the origin of life along the way. Perhaps I did not experience the drama of "transcending time and space" that I sought in high school, but the generosity of the Japanese astronomy community has made mine a reasonably enjoyable trip, nonetheless. I don't know if my cruise along the fringes of astronomy will be useful to the Astronomical Society of Japan, but I hope I can serve my two-year term as president without hindering our younger society members.