On September 30, 2025 (Japan time), the Japan Aerospace Exploration Agency (JAXA) and the Centre National D'Etudes Spatiales (CNES) signed an Implementing Arrangement (IA) concerning cooperative activities related to lunar seismometer network studies.

From left: Yamakawa Hiroshi, President of JAXA; Fujimoto Masaki, Director of ISAS, JAXA; Lionel Suchet, Chief Operating Officer of CNES; Francois Jacq, President of CNES. (Credit: JAXA)

The signing ceremony was held on the 76th International Astronautical Congress (IAC 2025) in Sydney, Australia. The IA was signed by Fujimoto Masaki, Director of ISAS, JAXA, and Lionel Suchet, Chief Operating Officer of CNES, in the presence of Yamakawa Hiroshi, President of JAXA, and Francois Jacq, President of CNES.

A lunar seismometer network is a system for observing moonquakes (lunar earthquakes) by deploying multiple seismometers on the lunar surface and collecting seismic data, thereby enabling the study of the Moon's internal structure and activity. Through international cooperation, it enables the creation of outstanding scientific achievements on the lunar surface.

Under this IA, JAXA and CNES will jointly explore long-term cooperation scenarios for participation in the establishment of the system, and will conduct a feasibility study on the development of a lunar seismometer and its installation on a Japanese lunar lander.

The cooperative activities based on this IA will be carried out within the framework of the JAXA-CNES Inter-Agency Agreement. Through this collaboration, JAXA will continue working with CNES to contribute to the advancement of international lunar exploration science.