Jupiter's Volcanic Moon Io Has a Collapsible Atmosphere

Jupiter's active moon Io has a collapsible atmosphere: New views show the satellite's shroud of sulfur dioxide freezing when Io enters its planet's shadow each day and converting back to gas when the moon emerges. "This confirms that Io's atmosphere is in a constant state of collapse and repair, and shows that a large fraction of the atmosphere is supported by sublimation of sulfur dioxide ice [when it turns to gas]," John Spencer, a researcher at Southwest Research Institute (SwRI) in Colorado