"A recent analysis of another world found that it could be a water world..." by MICHELLE STARR via sciencealert headline image credit: NASA/ESA/Leah Hustak (STScI) Two worlds orbiting a tiny star 218 light-years away appear to be of a kind unlike anything we have in our Solar System. The exoplanets are named Kepler-138c and Kepler-138d. Both are around 1.5 times the radius of Earth, and both appear to be soggy worlds consisting of thick, steamy atmospheres and insanely deep oceans, all wrapped around a rocky-metallic interior. "We previously thought that planets that were a bit larger than Earth were big balls of metal and rock, like scaled-up versions of Earth, and that's why we called them super-Earths," says astronomer Björn Benneke of the University of Montreal. "However, we have now shown that these two planets, Kepler-138c and d, are quite different in nature: a big fraction of their entire volume is likely composed of water. It is the first time we observe planets that can be