Jupiter and the Gallileans

This round blurry little blob is the planet Jupiter as caught in my Nikon Coolpix fully zoomed up
You cannot miss Jupiter in the night sky at the moment (in the UK, at least)
I am amazed that I caught the 4 largest moons with it
They are known as the Gallileans as they were first discovered by the Italian Astronomer Gallileo
I'm not 100% sure which one's which as I have not been able to observe on a few consecutive evenings
They are named Ganymede, Callisto, Europa and Io
Io is the most volcanically active place in the solar system
Europa is an ice world that scientists believe to have liquid water underneath it's crust
Ganymede is the largest moon in the solar system
And Callisto *shrugs* it's just Callisto :-)