14:45 〜 15:00
[MZZ40-05] 惑星防災探査機HeraとRAMSES: 現状報告と日本との協働
★招待講演
キーワード：惑星防衛、ヘラ、ラムセス
We are entering a new era of international collaboration in planetary defense. The recent discovery of the small asteroid 2024 YR4, which briefly reached a high rating (i.e., 3) on the Torino scale, underscores the reality of asteroid impact hazards. In recent years, many asteroid missions have significantly contributed to our understanding of how to mitigate these threats. Although the primary objectives of Hayabusa, Hayabusa2, and OSIRIS-REx were focused on fundamental science, particularly remote sensing of asteroids and sample return to Earth, these missions have also provided invaluable insights into planetary defense. One notable example is the artificial impact experiment conducted by Hayabusa2, in which the Small Carry-on Impactor (SCI) created a 15-meter crater on the rubble-pile asteroid Ryugu in April 2019 (Arakawa et al., 2020). This experiment has deepened our understanding of impact physics and asteroid surface properties, offering critical data for future impact mitigation strategies.
Building on the success of previous asteroid missions, NASA’s DART mission achieved a highly successful impact in September 2022, causing a measurable orbital change in its target, Dimorphos (Cheng et al., 2023). The resulting crater or impact-induced modifications on Dimorphos are expected to be significantly larger than those created by SCI (e.g., Raducan et al. 2023). A simple extrapolation of the SCI results is likely insufficient; therefore, follow-up observations with a dedicated spacecraft are essential. This will be carried out by ESA’s Hera mission, which is equipped with a comprehensive suite of scientific instruments, including optical, near infrared, and thermal infrared cameras, as well as two CubeSats (Michel et al., 2022). Launched in October 2024, Hera is expected to arrive at Dimorphos in late 2026. The spacecraft is in good condition, has successfully completed its initial in-flight observations, and is scheduled to conduct observations of Mars, Deimos, and Phobos in March 2025. This presentation will provide an update on the status and progress of the Hera mission.
Since Hera is the goddess of fertility, the Hera mission already has an “offspring”: the Rapid Apophis Mission for SEcurity and Safety (RAMSES) mission (Küppers et al., 2024). In April 2029, the near-Earth asteroid Apophis will pass within approximately 31,600 km of Earth, closer than the geosynchronous orbit. This rare event presents a unique opportunity to study the tidal interactions between a small asteroid and our planet. ESA is now working on RAMSES plan for observing Apophis during this close encounter, with JAXA considering a major contribution to the mission. The basic concept of RAMSES is to use the Hera’s design to reduce both cost and development time while maximizing scientific return. The mission concept and preparation are evolving rapidly, and we will provide an update on the latest developments in this presentation.
References: Arakawa, M. et al. (2020) Science, 368, 67-71; Cheng, A. et al. (2023) Nature, 616, 457-460; Michel, P. et al. (2022) PSJ, 3, 160; Küppers M. et al. (2024) EPSC, ID#2024-199; Raducan, S.D. et al (2024) Nature Astron., 8, 445-455.
Building on the success of previous asteroid missions, NASA’s DART mission achieved a highly successful impact in September 2022, causing a measurable orbital change in its target, Dimorphos (Cheng et al., 2023). The resulting crater or impact-induced modifications on Dimorphos are expected to be significantly larger than those created by SCI (e.g., Raducan et al. 2023). A simple extrapolation of the SCI results is likely insufficient; therefore, follow-up observations with a dedicated spacecraft are essential. This will be carried out by ESA’s Hera mission, which is equipped with a comprehensive suite of scientific instruments, including optical, near infrared, and thermal infrared cameras, as well as two CubeSats (Michel et al., 2022). Launched in October 2024, Hera is expected to arrive at Dimorphos in late 2026. The spacecraft is in good condition, has successfully completed its initial in-flight observations, and is scheduled to conduct observations of Mars, Deimos, and Phobos in March 2025. This presentation will provide an update on the status and progress of the Hera mission.
Since Hera is the goddess of fertility, the Hera mission already has an “offspring”: the Rapid Apophis Mission for SEcurity and Safety (RAMSES) mission (Küppers et al., 2024). In April 2029, the near-Earth asteroid Apophis will pass within approximately 31,600 km of Earth, closer than the geosynchronous orbit. This rare event presents a unique opportunity to study the tidal interactions between a small asteroid and our planet. ESA is now working on RAMSES plan for observing Apophis during this close encounter, with JAXA considering a major contribution to the mission. The basic concept of RAMSES is to use the Hera’s design to reduce both cost and development time while maximizing scientific return. The mission concept and preparation are evolving rapidly, and we will provide an update on the latest developments in this presentation.
References: Arakawa, M. et al. (2020) Science, 368, 67-71; Cheng, A. et al. (2023) Nature, 616, 457-460; Michel, P. et al. (2022) PSJ, 3, 160; Küppers M. et al. (2024) EPSC, ID#2024-199; Raducan, S.D. et al (2024) Nature Astron., 8, 445-455.