About JASMINE Project

JASMINE (Japan Astrometry Satellite Mission for Infrared Exploration) is a satellite for measuring the distances and apparent motions across the celestial sphere of stars around the central bulge of the Milky Way (Galactic nuclear region) with unprecedented precision. JASMINE has been selected by the JAXA Institute of Space and Astronautical Science (ISAS) as the unique candidate for the JAXA Competitive Middle-Class Science Mission No.3. Using a telescope with a primary mirror aperture of about 36 centimeters and a domestically produced infrared camera, the satellite will focus on an area of a few square degrees of the Galactic nuclear region. According to the current (December 2024) progress schedule in the Space Basic Plan established by the Cabinet Office in Japan, the launch of JASMINE is scheduled for the end of FY2031.

By observing infrared light that can penetrate the dusty nuclear region of the Milky Way, JASMINE will be able to obtain reliable measurements of annual parallaxes and other extremely small stellar motions on the celestial sphere with an accuracy of 25 microarcseconds (1 / 144,000,000 of a degree), and determine the distances and velocities of the many stars in the Galactic nuclear region 26,000 light-years away which are difficult to observe in visible light. The completely new "map" (including velocity information) of the stars in the Milky Way’s nuclear region obtained by JASMINE is expected to contribute to our understanding of not only the formation history of the Galactic nuclear structure, but also many other fields in astronomy including dark matter, black holes, and the overall evolution of the Milky Way Galaxy.

In summer and winter, when astronomical observations of the Milky Way's central region are difficult, JASMINE will search for Earth-like planets in the habitable zone around M-type stars, which are about one-fifth the size of the Sun. JASMINE will be able to continuously measure the brightness of the stars and reveal the presence of a planet by detecting a slight dimming of the brightness when a planet passes in front of the star (transit method).