Jupiter has four large moons – Io, Europa, Ganymede and Callisto – with diameters of more than 3000 kilometres. However, as of April 2023, we know it is also home to 91 additional small satellites.

Or perhaps more likely, look at under a microscope. The latest candidate for hosting nearby life is Jupiter’s moon, Io. Let’s take a look at what makes Io special, and what we might hope to ...