This series of false-color images obtained by NASA’s Cassini spacecraft shows the dissolving cloud cover over the north pole of Saturn’s moon Titan.
The images, obtained by Cassini’s visual and infrared mapping spectrometer (VIMS), cover 2006 to 2009, when Titan was transitioning from northern winter to northern spring. In 2006, the north polar cloud appeared dense and opaque. But in spectrometer images obtained around the 2009 equinox, when the sun was directly over Saturn and Titan’s equators and northern winter was turning into spring, the cloud appeared much thinner and patchier. The dissipating cloud allowed scientists to see the underlying northern lakes and seas, including Kraken Mare. The northern seas and lakes on the surface below, made of liquid hydrocarbons, look like dark jigsaw puzzle pieces in the false-color images. In data gathered by Cassini’s composite infrared mapping spectrometer to analyze temperatures on Titan’s surface, not only did scientists see seasonal change on Titan, but they also saw day-to-night surface temperature changes for the first time. Like Earth, the surface temperature of Titan, which is usually in the chilly mid-90 kelvins (around minus 288 degrees Fahrenheit), was significantly warmer in the late afternoon than around dawn.