Carbon oxides on Uranus' moon Ariel hint at hidden ocean, Webb telescope reveals

The surface of Uranus' moon Ariel is coated with a significant amount of carbon dioxide ice, especially on its "trailing hemisphere" that always faces away from the moon's direction of orbital motion. This fact presents a surprise because even at the frigid reaches of the Uranian system—20 times farther from the sun than Earth—carbon dioxide readily turns to gas and is lost to space.