Boundless curiosity—The great voyage toward the Solar System

Japan Agency for Marine-Earth Science and Technology (JAMSTEC)
Director, Group Leader, and Principal Scientist of the Biogeochemistry Research Center (BGC)
Member of the Hayabusa2 Project Sampler Team, Initial Analysis Team.
 
Dr. Yoshinori Takano
Born in 1975. Graduated in the Department of Chemistry at University of Tsukuba. Ph.D. in 2003. He has held positions at the National Institute of Advanced Industrial Science and Technology (AIST), the Institute for Research on Earth Evolution (IFREE) at JAMSTEC, and as Senior Scientist at the Institute of Biogeosciences (Biogeos), before assuming his current position. He is also currently a project associate Professor at Keio University. His awards include the Nishida Prize from Japan Geoscience Union and Organic Geochemistry Award from the association of Organic Geochemistry. He has contributed to numerous publications, including the first results for organic astrochemistry of Ryugu published on Science, Nature Astronomy, Nature Communications and the other important following papers.

In December 2014, the Hayabusa2 spacecraft started on its journey from the Tanegashima Space Center. After the total voyage of 5.2 billion kilometers, we recovered “the treasure box (Tamatebako)” containing samples of sand and rocks from the asteroid Ryugu in December 2020.
What does the carbonaceous asteroid Ryugu tell us? Let us introduce the prologue of the Ryugu story.

In this final installment of our special interview series, we spoke with Dr. Yoshinori Takano of JAMSTEC, member of the Sampler Team for collecting Ryugu samples and the Initial Analysis Team. He shared his insights about the initial analysis process and his passion for scientific research.
*Information current as of time of interview.

My specialty is chemistry. From a chemistry perspective, it’s really just a matter of using different measuring scales. For example, if we consider the Earth’s scale to be a 30-centimeter ruler, we can think of the Solar System on the scale of a one-meter ruler. Astronomy might operate on the scale of a tape measure.

At the core of my research is the field of organic chemistry such as organic astrochemistry and organic geochemistry. Broadly speaking, we want to connect our understanding of the universe and the Solar System to our knowledge of Earth and life itself.

What fascinates me most about the Solar System science is the prebiotic chemistry we can only observe in pristine abiotic processes. This is because we can potentially decipher the really-real chemical evolution and the primordial interaction among water, minerals, and organic molecules.

This is why carbonaceous asteroids, governed purely by physical and chemical processes, become critically important. And Ryugu perfectly meets the ideal conditions—it’s rich in water and organic matter, potentially holding information about the 4.6-billion-year history of our Solar System’s origins and chemical evolution. Uncovering Ryugu’s true nature is one of the Hayabusa2 Project’s most crucial objectives and will become part of our shared human knowledge. Being involved in this mission is the ultimate fulfillment as a researcher and embodies the true essence of being a scientist.

As a member of the Sampler Team collecting Ryugu samples, I was involved in system testing, sampling operation trials, evaluating system environment cleanliness, as well as sample recovery and on-site analysis in Australia. One of the biggest unexpected issues was the COVID-19 pandemic. The Sampler Team was forced to revise its schedule. Supply chain disruptions led to changes in some plans—an unexpected situation as we approached the final stages. There was growing tension over whether we’d even be able to reach the Hayabusa2 capsule recovery site in Australia.

After negotiations between the Japanese and Australian governments, the Sampler Team members were finally able to arrange departure on a chartered flight. After enduring multiple COVID tests, movement restrictions, and quarantine periods, we headed to an eerily quiet Haneda Airport late at night. Amid the tension and anxiety, we were surprised to discover that our chartered flight number was 8823 (spelling “Hayabusa”). The tension eased from everyone’s faces. I still vividly remember how touched we were by this thoughtful gesture.

After arriving in Australia and completing additional quarantine, we began our meticulous preparations. On December 6, we watched the fireball streaming across the sky like a meteor as it entered the atmosphere. That’s when it hit us that it had finally returned to Earth. Seeing the capsule in person after its six-year journey was a moving experience. Though I’d been involved with this project for nearly a decade, in that moment, we could see the emotion in the eyes of the Sampler Team members.

We’re right in the middle of the measurement stage. At JAMSTEC’s Yokosuka Headquarters, we’re measuring the abundance of light elements and stable isotope* ratios in the Ryugu samples. This helps us determine where these elements came from and how they’ve changed over time. The key to this research is certainty and evidence. The most exciting moments are when our measurements align with results obtained using different methods.

In fact, our research group at JAMSTEC Yokosuka Headquarters and the HORIBA research group are independently conducting cross-validation of certain specialized analyses. We call this “inter-laboratory comparison.” Working with microscale samples and conducting double-blind verification is a rare opportunity that comes perhaps once in a decade. We’re each validating the reliability of each other’s data.

The analysis of Ryugu samples isn’t just being conducted in Japan—we’re also collaborating with NASA. Members who were pursuing scientific research together in their 20s and 30s are now collaborating on cutting-edge science, each bringing their own strengths to the table. Nothing could be more reassuring. We’re looking forward to publishing our papers (Please see the references below.)
 

* Stable isotopes: Matter is composed of combinations of various elements such as carbon, nitrogen, and sulfur, with each element having a specific mass (atomic mass number). Atoms of the same element with different mass numbers are called isotopes, and those that exist stably in nature at fixed ratios are called stable isotopes.

Theory is certainly important. But without measurement, we can’t obtain real information. It’s ideal when theoretical research and actual measured data align. However, what’s fascinating is that in nature, predicted and measured values often differ. In such cases, there’s the possibility of unexpected discoveries we haven’t yet noticed. In other words, it can lead to serendipity. Those moments are truly exciting.

In verifying the origins and processes of matter, I value the results of measurement, the facts, over preconceptions.

During my junior high and high school days, I really loved chemistry. For instance, when discovering that water electrolysis produces hydrogen (H) and oxygen (O) in a 2:1 ratio, I remember feeling a sense of pure wonder—similar to that of discovering the beauty of prime numbers in mathematics. I would take apart dry cell batteries to extract the carbon rods and gather household items to build my own electrolysis apparatus. I would collect sour gas from natural sulfur found in an active volcano (Mt. Chausu). I’d go fossil hunting in mountain streams with a hammer in hand. In mathematics too, I enjoyed taking time to find a different solution to problems. Scientific book series written by leading experts captivated me with their vivid explanations, covering topics beyond what textbooks offered.

During my graduate studies, I had the opportunity to meet Dr. Stanley Miller at the University of California, San Diego—someone I had only known through his famous papers. The moment was very inspiring. As I delved deeper into chemistry—studying life, Earth, and space—I found joy throughout university, graduate school, and my professional career, and before I knew it, I’d arrived where I am today.

It comes down to “Do what you love, and you’ll excel at it.” In my case, I’ve always valued cultivating my curiosity and strengthening my capabilities. When you have something you’re truly passionate about, the path forward becomes clear on its own. It’s important to have the composure to even enjoy failures, and to gain experience by taking on various challenges. I believe that not only successes, but also the experience gained from failures, eventually becomes valuable assets.

I'll compare our conversation to baseball. After thorough preparation, when you step up to bat, it’s okay even if you swing and miss. You can always step up to the plate again. Rather than striking out without ever swinging, I’d rather take a big swing and face the challenge head-on.

The results of the analysis of Ryugu’s samples will continue to be published. And in 2023, NASA’s OSIRIS-REx mission is scheduled to return samples from asteroid Bennu. If there are commonalities between Ryugu and Bennu, we might be able to inductively generalize traits and material evolution of certain asteroids. If there are differences, it will expand our knowledge into previously unknown territories. Either way, it’s fascinating.

Just as we had the Age of Exploration in medieval times, we’re now in what you might call the “Age of Solar System Exploration.” In the 2020s, we can’t take our eyes off the Solar System science.

I hope they’ll cherish their curiosity and sense of enjoyment. Try writing down your dreams and aspirations in a journal or notebook. Then, share those dreams with the people around you. If you approach others with sincerity and gratitude, they’ll offer heartfelt advice, point out your blind spots, provide warm encouragement, and you’ll develop relationships where you can mutually grow. And someday, those dreams will become reality.

The world is waiting for ambitious ideas. To take on big projects, you need colleagues. Human connections are truly mysterious—looking back, there are many instances where my involvement in this project can be traced back to meeting someone at a particular time and place. Please treasure these meaningful encounters.

When I was in elementary school, Halley’s Comet made its close approach to Earth, and I remember thinking, “Wow, that’s amazing.” Now I’m working on Hayabusa2 alongside someone who led those Halley’s Comet observations—it’s quite moving. I’d be delighted if I could someday work alongside children and the young generation who were inspired by the Hayabusa2 Project.

Interview date: Late April 2022

(The original source of the content in this interview)

Takano, Naraoka, Dworkin et al. (2024) Primordial aqueous alteration recorded in water-soluble organic molecules from the carbonaceous asteroid (162173) Ryugu. Nature Communications, 15, Article number:5708. doi:10.1038/s41467-024-49237-6.

Yoshimura, Araoka, Naraoka et al. (2024) Breunnerite grain and magnesium isotope chemistry reveal cation partitioning during aqueous alteration of asteroid Ryugu. Nature Communications, 15, Article number:6809. doi:10.1038/s41467-024-50814-y.

Zeichner, Aponte, Bhattacharjee et al. (2023) Polycyclic aromatic hydrocarbons in samples of Ryugu formed in the interstellar medium. Science, 382, 1411-1416. doi:10.1126/science.adg6304.

Yoshimura, Takano, Naraoka et al. (2023) Chemical evolution of primordial salts and organic sulfur molecules in the asteroid 162173 Ryugu. Nature Communications, 14, Article number: 5284. doi:10.1038/s41467-023-40871-0.

Oba, Takano, Dworkin, Naraoka (2023) Ryugu asteroid sample return provides a natural laboratory for primordial chemical evolution. Nature Communications, 14, Article number:3107. doi:10.1038/s41467-023-38518-1.

Naraoka, Takano, Dworkin et al. (2023) Soluble organic molecules in samples of the carbonaceous asteroid (162173) Ryugu. Science, 379, eabn9033. doi:10.1126/science.abn9033.

Okazaki, Miura, Takano, Sawada et al. (2022) First asteroid gas sample delivered by the Hayabusa2 mission: A treasure box from Ryugu. Science Advances, 8, eabo7239. doi:10.1126/sciadv.abo7239.

Tachibana, Sawada, Okazaki, Takano et al. (2022) Pebbles and sand on asteroid (162173) Ryugu: In situ observation and particles returned to Earth. Science, 375, 1011-1016. doi: 10.1126/science.abj8624.