The Curiosity rover's curious nature has led it to discover that there may have been a flow of water on Mars in ancient times, according to CNN.
Curiosity has come across stones in conglomerate rock. The rocks are broken into pieces, looking as if someone had taken a jackhammer to concrete.
Scientists have concluded that the rock was "formed in the presence of water," and that the water can be characterized as "being a vigorous flow."
Around one particular bedrock, named Hottah, after the lake of the same name in Canada, Curiosity has found rounded gravels that were likely subject to a sediment transport process.
Because the gravels are too large to have been carried by wind, it is probable that the rocks were transported by a stream of water.
Another bedrock, named Link, has similar gravels.
Curiosity science co-investigator William Dietrich of the University of California, Berkeley, said the water was probably between ankle and hip deep.
It is believed that the water and sediment flowed down the crater into an alluvial fan. In certain parts, the fan looks as though it had extended down to the area where Curiosity landed.
Dietrich said it is difficult to tell how long the water flowed. Estimates have ranged from "thousands to millions of years," he said.
While scientists have used other data from past Mars missions to determine if water did exist on the planet, this recent Curiosity discovery is the first observation of "streambed material."
The Hottah rock formation looks as if there was an earthquake or other disturbance that penetrated the rock bed, but there are no plate tectonics on Mars.
What is most likely the cause of the disturbance is a small impact that occurred near the outcrop, lifting the rock beds and rotating them.
Curiosity did not use any chemistry tools to examine the rocks, scientists have made all judgments on the discovery through looking at the photos.
Now the rover has traveled three-quarters of the way between Hottah and Glenelg. Glenelg is its next stop, and was chosen as a target because it has three types of interesting terrain, including layered bedrock.
Scientists believe this is a good place for Curiosity to try out its drill.
Curiosity's final destination is Mount Sharp, a 3-mile-high mountain that contains layers of sediment, enabling more opportunities to search for organic molecules.