[LINK] "Orbiting Ganymede and Europa"

[rfmcdonald]

The prospect of sending probes to the Jovian system--NASA probe to Europa orbit and an ESA probe to Ganymede orbit--is discussed by Paul Gilster at Centauri Dreams. Might there be a joint strategy for exploring these two interesting worlds of the Jovian system?

ESA’s own report on the EJSM is being presented to the European public this month, making the case for journeys to two icy moons that have long captured the imagination. Both Ganymede and Europa are thought to have sub-surface oceans, Europa’s covered with what may be a relatively thin shell that presents a dynamic surface, one that captures its history on the ice in the form of movements of ice ‘rafts’ and upwellings from the liquid below. One task of the EJSM will be to identify possible landing sights for future craft, but onboard instruments including ice-penetrating radar should also tell us much about the extent of the water under the ice. Unlike Ganymede, Europa’s ocean is thought to be in contact with the rocky mantle below.

Ganymede, on the other hand, is believed to feature a thicker ice shell, its ocean trapped between ice above and below. The contrast between the internal structures of these two worlds should make for fascinating observation, and we’ll also learn about the magnetic field that sets Ganymede apart from other Solar System moons. The plan is for both orbiters to study Io and Callisto as well, adding to our knowledge of the Jovian system and potentially contributing to our understanding of gas giants around other stars. Between the two craft, we would have 21 complementary instruments to map Jupiter’s interactions with its largest moons.

Go, read.

Question: Does anyone know of any plans to send probes to Callisto or Io? Both worlds are interesting, too, Callisto somewhat like a colder Ganymede and Io being famously volcanic, though I can imagine the Jovian radiation belts at Io's orbit might inhibit probes.