Areas where the Cassini radar has observed transient surface liquid in Titan’s south polar region. The top two images are located near (60S, 210W) and were obtained in December 2007 and May 2009. Empty lake features are outlined in red and filled lakes, observed in the 2007 image, are outlined in cyan. The lake features disappear between observations. The bottom row consists of images near (69S, 90W) obtained in Oct. 2007 and Dec. 2008. Empty lake features observed in Dec. 2008 are outlined in red. The empty lake features in the bottom-left section of the image are dark in Oct. 2007, consistent with liquid-filled lakes. In the Dec. 2008 image the brightness of these features are indistinguishable from the empty lakes in the upper-right section of the image (which are bright in both observations), suggesting surface change. | Universe Today