Europa io moons orbiting Jupiter, captured by the Cassini space probe #space #planets #science

Credit: NASA-JPL’s @kevinmgill
moons
The difference is 155,000 miles. They’re about the same size with Io a little larger. The cool thing about these moons and another of Jupiter’s moon called Ganymede is that these three moons are in resonance – every time Ganymede orbits Jupiter once, Europa orbits twice, and Io orbits four times, exactly. So the moon in the background is Io.