Artist’s concept of a type of sub-Neptune exoplanet (a water world, in this case called a Hycean world). Such worlds may have global oceans and hydrogen atmospheres. Image via Amanda Smith/ University of Cambridge.
Water worlds? Or thick atmospheres?
Water is common in our solar system. We find it in both liquid and ice form, on Earth and other planets. And water is key to life as we know it. How about in distant solar systems? How many exoplanets – worlds orbiting distant stars – have water? Is water on exoplanets common … or rare? We don’t know yet, in part because it’s been hard to tell the difference between an ocean planet and one with a thick hydrogen atmosphere. Now, in a study being called a potential breakthrough, a team of researchers has figured out a way to test for water on sub-Neptune exoplanets, including some of the larger super-Earths.
The study has been accepted for publication in the peer-reviewed Astrophysical Journal Letters. It can currently be read in preprint form on arXiv. The new research comes from Caltech, MIT, and other institutions. Planetary scientist Renyu Hu at NASA’s Jet Propulsion Laboratory is the lead author. Hu told EarthSky ...