Japan Geoscience Union Meeting 2025

Presentation information

[E] Oral

L (Section Leading) » Section Leading

[L-01] Space and Planetary Science Lecture

Sun. May 25, 2025 10:45 AM - 12:15 PM Convention Hall (CH-A) (International Conference Hall, Makuhari Messe)

convener:Taishi Nakamoto(Institute of Science Tokyo), Yoshizumi Miyoshi(Institute for Space-Earth Environmental Research, Nagoya University), Makiko Ohtake(University of Aizu), Chairperson:Makiko Ohtake(University of Aizu), Yoshizumi Miyoshi(Institute for Space-Earth Environmental Research, Nagoya University), Taishi Nakamoto(Institute of Science Tokyo)

10:50 AM - 11:30 AM

[L01-01] Observing the Cradles of Young Planetary Systems

★Invited Papers

*Ryo Tazaki1 (1.University of Tokyo)

Since the groundbreaking discovery of the first exoplanet orbiting a Sun-like star in 1995, more than 5,000 exoplanets have been identified. However, the process of planetary system formation remains largely unknown. Planets are thought to form within protoplanetary disks surrounding young stars—the cradles of planetary systems. The building blocks of planets are initially submicron-sized dust grains inherited from the diffuse interstellar medium. These tiny grains must grow into kilometer-sized objects, known as planetesimals, which then continue to grow through mutual collisions, eventually forming planetary-sized bodies. One of the key unanswered questions in planet formation is when, where, and by what mechanisms planetesimals form within disks.

Over the past decades, observations of protoplanetary disks have advanced significantly, providing crucial insights into grain growth and planetesimal formation. By utilizing both ground-based telescopes, such as the Very Large Telescope and the Atacama Large Millimeter Array, and space-based telescopes, including the Hubble Space Telescope and the James Webb Space Telescope, we can study dust grains in disks across a wide range of wavelengths, from optical to millimeter, revealing their physical, chemical, and mineralogical properties.

In this lecture, I will present our recent efforts to unravel the still-mysterious mechanisms of dust growth through multi-wavelength observations of protoplanetary disks using various observational facilities. In particular, I will explain why multi-wavelength observations are crucial for extracting key information about dust grains and their evolution. Finally, I will discuss future prospects in this field and highlight some of the remaining open questions.