Ancient canals "Aram Chaos" basin
About 4.6 billion years ago, Mars was still quite young, as was Earth, and all kinds of large objects were smashing into other objects. A huge asteroid 175 miles wide crashed into Mars and left a basin now called Aram Chaos.
Sand dunes blowing over polar ice
As hundreds of millions of years passed, alot of space debris floated into this basin - volcanic ash, windblown dust, ash. The Martian climate was wetter then, and this crater filled with water which likely froze as the climate shifted and cooled, just like on Earth.
Channels carved by ancient floods
Then something triggered the ground ice to melt. Perhaps it was residual trapped heat from the impact, or most likely, molten rock moved into the fractured ground below the basin. Whatever happened, the ground-ice melted and in a geological instant, a chaotic network of valleys, hills and mesas were formed in Aram. Surging flood-waters on Mars carved many narrow channels.
Winds shifting in dunes Lava channels
A dramatic story gets more so: The existence of water and underground oceans on Mars has been proven accurate, yet what else could this reveal? In the deposits found in Aram Chaos, NASA has been examining layers of sediment. Data taken with TES (Thermal Emmission Spectrometer) on NASA's Mars Global Surveyor Orbiter revealed a widespread expanse in Aram of an iron-oxide mineral called hermatite. Hermatite forms in conjuction with water, which has caught the attention of scientists looking into the existence of past life on Mars, which seems almost a certainty, in some microbial form.
Another crater where water-minerals found
One of our Mars rovers, Opportunity, was sent to this basin area, and is relaying evidence of sulfate deposits, a great deal of them - more water-related minerals.
Where water once flowed abundant
Escaping meltwater is a fairly common process on Mars. More evidence for ancient waters. What this means about the kind of life we envision Mars once nourished is only limited by your imagination .....