Astronomers at Penn State 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 Hubble observations are the first detections of this “snow-out” process, called a “cold trap,” on an exoplanet. This discovery, and other observations made by the Penn State team, provide insight into the complexity of weather and atmospheric composition on exoplanets, and may someday be useful for gauging the habitability of Earth-size planets.