The NASA rover Curiosity acted as a detective on Mars this summer and investigated an area once filled with streams and lakes on the red planet.
The rover landed on Mars seven years ago and has since sent thousands of images, wandered 13 miles and climbed 1,207 feet in its current home on the side of Mount Sharp. This function is located within the Gale crater, where once upon a time streams and lakes could be found billions of years ago.
Gale Cater is a vast and dry ancient lake bed with a 16,404 foot high mountain in the center. The peak of Mount Sharp is higher than the edge of the crater.
Now, Curiosity is studying the clay minerals left after the disappearance of the water. He punched 22 surface samples.
"This area is one of the reasons we came to the Gale Crater," said Kristen Bennett of the US Geological Survey. "We have been studying orbiter images of this area for 10 years and we are finally able to take a closer look."
During his mission, Curiosity met most of the clay minerals on Mount Sharp. The minerals were detected for the first time by the Orbita reconnaissance of Mars years before Curiosity was launched.
Now that Curiosity is able to conduct field surveys, he has discovered more clay minerals, which is leading mission scientists to wonder why some were evident at the Orbiter and others not.
During the summer, Curiosity went through a "pebble parking lot" and studied other unique geological features on Mars. Recently, the rover's camera captured a view of the spur of Teal Ridge and Strathdon, a rock composed of layers of undulating sediments that could have been sculpted by wind, water or both.
"We are witnessing an evolution in the ancient lake environment recorded in these rocks," said Valerie Fox, co-director of the clay campaign at the California Institute of Technology. "It was not just a static lake. It is helping us move from a simplistic view of Mars from wet to dry. Instead of a linear process, the history of water was more complicated."