Mystery of Alien Worlds 2021 Science Exoplanets, strange worlds outside our solar system. We're discovering the cosmos is full of alien planets. Alien worlds that challenge our understanding of planetary systems. Hellishly hot worlds, violently colliding worlds, worlds getting eaten by their stars. There's much, much more out there than we had ever imagined. Exoplanets are shaking up our understanding of the universe. The cosmos is a chaotic array of the odd, the weird, and the wonderful. The more we find, the less we know.