Premise: Aluminium . By mass , aluminium makes up about 8 % of the Earth 's crust ; it is the third most abundant element after oxygen and silicon and the most abundant metal in the crust , though it is less common in the mantle below . Despite its prevalence in the environment , no known form of life uses aluminium salts metabolically , but aluminium is well tolerated by plants and animals . The Galilean moons are the four largest moons of Jupiter -- Io , Europa , Ganymede , and Callisto .
Hypothesis: Aluminium is prevalent on the moons of Jupiter.
Label: NEUTRAL