Wet planet Mars
NASA has announced that Mars has flowing water. It is found in subsurface flows, is rather briny, and only flows during summer warm weather (temperatures at or above -10 degrees Fahrenheit, -23 degrees Celsius). The strongest evidence are dark streaks called “recurring slope lineae” (RSL) that show up on the faces of crater walls periodically.
While the water is too salty to be drinkable, it does increase the likelihood of present-day life on Mars. And it might make a good margarita, assuming stranded Martian astronaut Mark Watney has something to flavor it other than potato.