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My main interest is in explosive phenomena in the universe. Today, throughout the universe, we are finding explosions, and long, thin, super-high-speed streams of gas called jet phenomena. These events are likely associated with the formation of celestial bodies. I've been involved in studying the Sun, the star closest to us, for twenty years, because solar research can give us important clues to understanding eruptive phenomena throughout the universe.
Today, we are discovering that the Earth is greatly affected by the Sun. For example, a magnetic storm caused by a solar explosion can trigger events ranging from satellite malfunction to serious electrical blackouts on our planet. I believe that solar Observation is very important not only for solving the mysteries of the universe but also for our benefit on Earth. To this end, I am also doing basic research on space weather forecasting. Hinode (SOLAR-B) has the most advanced solar Observation instruments ever built, which I am sure will benefit space weather forecasting. I would like to use data from Hinode to improve forecasting, so that the benefits of solar Observation will be recognized by the general public, too.
Yohkoh proved the existence of magnetic reconnection (explosive energy release caused by reconnection of magnetic field lines) in solar flares, and I'd like to further explain the physics of this phenomenon with Hinode. With reconnection, gas is violently ejected, and I'm very curious about the speed with which some of it reaches the Earth. Yohkoh couldn't measure this, but I think Hinode will be able to do so for the first time.
I also want to clarify the mechanism of coronal heating. The corona, where solar flares occur, is extremely hot - at a few millions degrees - even without large flares. There are two explanations for this under debate. One theory is that heat is produced by oscillations called Alfvén waves, which are carried along magnetic field lines. The other one proposes that coronal heating is due to explosions of nano-flares. Both Alfvén waves and nano-flares are theoretical and have never been directly observed, but we are hoping that Hinode will be able to do so.
I haven't been involved in a lot of research on magnetic fields, but I'm very interested in using the Hinode instruments to study sunspots and the nearby magnetic flux in the photosphere. This area will be a new frontier for me. I'm excited about the possible detection of the reconnection phenomenon in the photosphere.
Yohkoh taught us that solar activity and explosions are much more violent than expected.
After its launch in 1991, I was involved in Yohkoh operations at the National Astronomical Observation of Japan (NAOJ). It was my daily routine to check whether the satellite was functioning properly and to observe unusual events on the solar surface. It was always thrilling to watch the real Sun, and I loved doing it. Among all the discoveries made by Yohkoh, what excited me most was the magnetic reconnection phenomenon. It was an utterly moving moment to find a flare cusp structure - as had been predicted to occur after reconnection. I'm originally a theoretical scientist, so I have studied various phenomena by computer simulation.
According to my calculations, there should have been intense plasma ejections above the cusp, but I couldn't see any. So I analyzed all the data anyway, even some that wouldn't likely be used because of overexposure. And then, as theoretically predicted, I finally found many instances of plasma blown up above the flare loops (plasmoid phenomena). Magnetic reconnection theory has been debated around the world for many years, so it was indeed a great moment when I was able to find a piece of supporting evidence from the shape observed by Yohkoh. Having said that, the discovery is sometimes criticized as “unsubstantiated data,” as even the speed of magnetic reconnection cannot be measured. I'm expecting Hinode will determine the speed, and explain more details of magnetic reconnection.
Everybody enjoys beautiful images, and some astronomical photos are soothing to look at. I believe this is an important aspect of astronomy, so apart from our annual Open House, we also invite the general public to our star-watching parties, which are run with the cooperation of astronomy fans. We're aiming to hold such parties every couple of months, and data from Hinode will soon be on display as well. My Kwasan Observation, located behind the famous Kiyomizu Temple in Kyoto, was established in 1929. We have a hundred-year-old telescope that still performs well. We also let the general public, including schoolchildren and teachers, try out Observational instruments that aren't being used for our regular research. Last time, seven hundred people applied for sixty seats at this new event. The value of continuing this type of activity is obvious, so I'd certainly like to make it a regular event.
Hinode will probably change this, but at the moment Japan is still behind in solar research. We're conducting world-class research thanks to Yohkoh, but there are very few scientists working in this field. I see that Yohkoh has inspired many people and changed the research conditions, but the fact is that there are only about three universities in Japan where you can do a Ph.D. in solar science or similar fields. Since many scientists continue the research they started in graduate school, and Japanese scientists tend to focus on a single field in their lifetime, there will be few successors to carry on our solar research unless something is done.
Fifty years ago, solar science was at the cutting edge of astrophysics. But since then, the advancement of Observation technology has made it possible for us to see phenomena in more distant galaxies, stretching the frontiers of astronomy. I think this has contributed to the decline in numbers of solar scientists today. As solar activity has an enormous influence on the Earth, the Sun is an essential part of Earth research. This is why I would like to see further collaboration in research on the Sun and the Earth at JAXA. To increase the number of people with strong knowledge of the Sun, I would like JAXA to support scientists across Japan.
JAXA has achieved great Observational results, and has also shown creativity in space education for children. I sincerely hope that JAXA will do more to share its experience with universities and other organizations. I think that members of JAXA will need to go out and educate university students in order to nurture future scientists. There are many ways to do this, and as long as the basic intent is genuine, I'm sure the efforts will be fruitful. A new relationship between JAXA and universities should also be encouraged, so that young Japanese scientists can make good use of Hinode data. I will continue my efforts to advance the understanding of solar research.