James Webb Space Telescope (JWST) and the Hubble Space Telescope are joining forces to observe Io

In a collaborative effort, the James Webb Space Telescope (JWST) and the Hubble Space Telescope are joining forces to observe Io, one of Jupiter's most volcanic moons. The data collected by these telescopes will be utilized by NASA's Juno spacecraft to further explore the intriguing moon and its contribution to plasma in Jupiter's environment.

The Southwest Research Institute (SwRI) has been granted observing time on both the JWST and Hubble by the Space Telescope Science Institute to conduct this investigation. The SwRI team plans to gather data on Io using Hubble during 122 of the telescope's orbits around Earth, supplemented by nearly five hours of observing time with the JWST. The timing of this project is crucial as Juno is scheduled to make multiple flybys of Io in the coming year, providing rare opportunities to combine in-situ and remote observations.

The primary objective of this study is to gain new insights into Io's volcanic activity, plasma-moon interactions, and the neutral gas and plasma populations that exist within Jupiter's vast magnetosphere. Io's surface is known to be dotted with hundreds of actively erupting volcanoes, spewing lava into its thin, waterless atmosphere. The extreme volcanic activity on Io is believed to be a result of tidal forces generated by the gravitational influences of Jupiter and other Jovian moons.

These tidal forces cause Io's surface to rise and fall significantly, with variations of up to 330 feet (100 meters). Such volcanic activity impacts the entire Jovian system, as particles from Io's atmosphere become trapped in Jupiter's magnetic field. These escaping atmospheric gases, which are ionized, contribute to the formation of the Io Plasma Torus (IPT), a doughnut-shaped cloud of charged particles surrounding Jupiter. Collisions between electrons and ions in the IPT produce ultraviolet radiation detectable by telescopes on Earth and in space.

To better understand the IPT and its connection to Io's volcanism, comprehensive investigation of the Jovian system as a whole is necessary. The SwRI team believes that studying the system as an integrated entity, rather than individual components, will provide valuable insights. Juno, which has been exploring Jupiter and its environment since 2016, has already completed several flybys of Io and other moons, including Europa. However, the data collected by Juno alone is insufficient, necessitating the combined efforts of the JWST and Hubble.

On September 20, Juno will make a distant pass of Io, enabling simultaneous observations by Hubble and the JWST. This unique opportunity allows the telescopes to observe what Juno sees from a distance, providing a comprehensive view of the Jovian system. The last time a holistic approach was taken in studying Io was during a series of Galileo spacecraft flybys supported by Hubble in 1999 to 2000. The SwRI team is confident that combining Juno's in-situ measurements with remote-sensing observations will significantly advance our understanding of Io's role in driving phenomena within the Jupiter system.

While future missions to Jupiter and its moons, such as the Europa Clipper and Jupiter Icy Moons Explorer (JUICE), are planned for arrival between 2029 and 2031, none of these missions will include a flyby of Io. Therefore, the next opportunity for similar observations is not expected until at least the 2030s, making the current collaborative effort between Juno, JWST, and Hubble a crucial undertaking in unraveling the mysteries of Io and its relationship with Jupiter's environment.