Astronomers have used the Hubble Space Telescope to find a blistering-hot giant planet outside our solar system where the atmosphere 'snows' titanium dioxide -- the active ingredient in sunscreen. These observations are the first detections of this 'snow-out' process, called a 'cold trap,' on an exoplanet. The research provides insight into the complexity of weather and atmospheric composition on exoplanets, and may someday be useful for gauging the habitability of Earth-size planets.