Earth Sky | A livable water world doesn't have to be like Earth
View bigger. | Artist’s concept showing what some of the habitable water worlds in our Milky Way galaxy might look like. A new study shows they don’t need to all look the same. Notice the Earth on the far right. Image via NASA/Wikimedia Commons. Earthly life requires water. So scientists contemplating life outside our solar system have traditionally thought of watery exoplanets, similar to our own aquatic world. An exoplanet that is similar to Earth – in terms of atmosphere, distance to stars, mass, etc. – suggests a possible habitable world. But scientists said in late June 2022 that long-term liquid water would not have occurs under conditions similar to Earth. Exoplanets can be a little bigger and may not even be located near a star! The new study comes from researchers at the University of Bern, the University of Zürich and PlanetS’s National Center for Competence in Research (NCCR). This suggests that several different exoplanets from Earth may be able to retain liquid