Scientists don't want to risk a run - in between Juno and any of the icy moons, such as Europa, which could conceivably harbor life in its buried liquid water ocean.
Scientists announced Thursday that measurements from NASA's Cassini spacecraft detected hydrogen gas, a key energy source for microbial life, in a plume gushing from a vast liquidwateroceanburied beneath the icy shell of Saturn's moon Enceladus.