Cowards Anonymous points out news that studies based on data from the Mars Reconnaissance Orbiter have found that vast regions of Mars contained rivers and lakes
when the planet was young. The studies also suggest that the water existed for quite some time, often in standing pools, which are conducive to the formation of basic organic matter. NASA provides a color-enhanced photo of a delta within a crater
"The clay-like minerals, called phyllosilicates, preserve a record of the interaction of water with rocks dating back to what is called the Noachian period of Mars' history, approximately 4.6 billion to 3.8 billion years ago. This period corresponds to the earliest years of the solar system, when Earth, the moon and Mars sustained a cosmic bombardment by comets and asteroids. Rocks of this age have largely been destroyed on Earth by plate tectonics. They are preserved on the moon, but were never exposed to liquid water. The phyllosilicate-containing rocks on Mars preserve a unique record of liquid water environments possibly suitable for life in the early solar system."