The first of the gas-giant orbiter’s back-to-back flybys will provide a close encounter with the massive moon after over 20 years.
On Monday, June 7, at 1:35 p.m. EDT (10:35 a.m. PDT), NASA’s Juno spacecraft will come within 645 miles (1,038 kilometers) of the surface of Jupiter’s largest moon, Ganymede. The flyby will be the closest a spacecraft has come to the solar system’s largest natural satellite since NASA’s Galileo spacecraft made its penultimate close approach back on May 20, 2000. Along with striking imagery, the solar-powered spacecraft’s flyby will yield insights into the moon’s composition, ionosphere, magnetosphere, and ice shell. Juno’s measurements of the radiation environment near the moon will also benefit future missions to the Jovian system.
Ganymede is bigger than the planet Mercury and is the only moon in the solar system with its own magnetosphere—a bubble-shaped region of charged particles surrounding the celestial body.
“Juno carries a suite of sensitive instruments capable of seeing Ganymede in ways never before possible,” said Juno Principal Investigator Scott Bolton of the Southwest Research Institute in San Antonio. “By flying so close, we will bring the exploration of Ganymede into the 21st century, both complementing future missions with our unique sensors and helping prepare for the next generation of missions to the Jovian system—NASA’s Europa Clipper and ESA’s [European Space Agency’s] JUpiter ICy moons Explorer [JUICE] mission.”
Juno’s science instruments will begin collecting data about three hours before the spacecraft’s closest approach. Along with the Ultraviolet Spectrograph (UVS) and Jovian Infrared Auroral Mapper (JIRAM) instruments, Juno’s Microwave Radiometer’s (MWR) will peer into Ganymede’s water-ice crust, obtaining data on its composition and temperature….[ ]