The Juno spacecraft, operated by the space agency, has been progressively approaching Jupiter's moon Io, a geologically active celestial body known for its volcanoes and lava, Mashable reported. Io's volcanic landscape can be attributed to its position in an ongoing gravitational battle between the colossal Jupiter and two other significant moons, Ganymede and Europa, the latter of which potentially contains a substantial ocean. This constant gravitational tug-of-war generates intense internal heat within Io, a moon slightly larger than ours