There has been evidence of water once existed on Mars before, but these new images showing rocks that contain ancient streambed gravels are the very first of their kind.
From observing the size and shape of rocks and gravel from images provided by Curiosity, scientists were able to tell that the stream of water was moving with a speed of about 3 feet per second (0.9 cm per second) and was anywhere between ankle and hip deep.
Scientists say, that from the shapes and sizes of some stones it is quite obvious that they traveled a long distance and couldn't be brought by the wind but were transported by the flow of a water. The gravels resemble the gravels on Earth and range in sizes from a grain of sand to the size of a golf ball, some have sharper angles, others are round.
A long water bed can sure be environment suitable for living organism. Nonetheless Curiosity's prime mission is still the slope of Mount Sharp in Gale Crater where clay and sulfate minerals have been detected and can serve as potential ingredients for forming a life.
Video explaining the relationship between river fans found in California’s Death Valley on Earth and similar fans in Gale Crater on Mars.
It means that we now have even stronger evidence once actually was water on Mars, which does improve chances of finding evidence of life on Mars as well.