Our solar system is made up of the sun, the eight known planets and the dozens of moons that circle those planets. But then there are innumerable asteroids, comets and dwarf planets wandering around.

Jupiter’s moon Io is the most volcanically active place in the solar system. Let me tell you just how volcanic it is.

From meteorites that impact Earth, to a moon that orbits backwards, to an imposter lurking in the asteroid belt, a variety of strange, wandering worlds are rewriting what we know – and even how we ...