Scientists, including Waterloo Centre for Astrophysics’ Professor Lisa Dang, have discovered a huge cloud of helium gas is escaping from the atmosphere of the exoplanet WASP-121 b, an “ultra-hot Jupiter.” Using the James Webb Space Telescope (JWST), scientists found that the helium stretches into long tails in front of and behindthe planet as it orbits around its star. The planet is losing atmosphere in dramatic ways, but current models can’t fully explain the observed structure, leaving scientists searching for more information.