Today's Image of Mars was taken by HiRISE and shows a channel-like formation with numerous branches being interrupted by a crater. The feature has a distinctive pink color, and retains a warm temperature at night, which suggests that it is exposed bedrock and not fine-grained materials.
The pink patches in the image below are similar in color, morphology, and geologic setting to larger deposits on Mars that are thought to consist of chloride salts like Sodium Chloride, Magnesium Chloride, and Potassium Chloride. The important thing to note about the presence of chloride salts is that they could only have been deposited by the evaporation of salty water.
Clicking on this image will take you to the original high resolution image from HiRISE. [See their caption for the image]