The Curiosity rover, which landed on Mars in 2012, has explored various aspects of Gale Crater on Mars to understand more about this transition from hot and wet to dry and very cold.
The latest study, gathered from data captured by one of the rover’s instruments, suggests that Mars actually went back and forth between wetter and drier times before completely losing its surface water about three billion years ago.
Curiosity has been steadily climbing 3-mile Mount Sharp, located in the center of Gale Crater, since 2014.
An instrument called ChemCam sits on the rover’s mast and includes a high-resolution camera and a laser that can vaporize rocks to help the rover analyze their chemical makeup. ChemCam has an infrared-colored laser that can heat stone pieces to 18,000 degrees Fahrenheit. This vaporizes the rock and creates plasma, essentially allowing scientists to look into the minerals and chemicals that make up the rock and look back into the geological history of the planet.
The camera on ChemCam was used to capture observations of Mount Sharp’s terrain, revealing parts of Martian past as the rock varies.
A History Lesson From Mars
Mount Sharp is an intriguing feature on Mars because it is one of the best ways the red planet recorded the history of its climate, water, and sediment.
“A primary goal of the Curiosity mission was to study the transition between the habitable environment of the past, to the dry and cold climate that Mars now has. . author on the paper and ChemCam team scientist at Los Alamos National Laboratory, in a statement.
Orbiters around Mars have previously captured information about the minerals on the slopes of Mount Sharp. Curiosity’s data has provided even more detailed observations of the sedimentary rock layers and revealed dry and wet spells about the planet’s past.
Curiosity detects major changes in layers
While Curiosity has climbed Mount Sharp, the layers have changed dramatically.
The base of Mount Sharp is made of clay deposited by the lake that once filled the crater. Above that are layers of sandstone that still hold evidence of how they were formed by wind-shaped dunes in drier times. Layers above reveal more floodplain deposits, indicating when wet conditions returned to Mars.
Curiosity’s observations show that these changes between wet and dry eras were large-scale events that alternated until the planet became permanently dry. Mount Sharp’s climate record has allowed Curiosity to focus on a time stretching from 2.9 billion to 3.7 billion years ago.
As the rover continues its mission, Curiosity will continue to climb the foothills of Mount Sharp and use its drill to further investigate the rock types and what they reveal. This could provide more insight into the cause of such drastic climate fluctuations.