(CNN) – Mars was a warm, wet planet that was probably capable of life billions of years ago. Something caused the planet to lose its atmosphere and turn into a harsh, frozen desert as it is today.
Rover Curiosity, which landed on Mars in 2012, explored various aspects of the Gale crater on Mars to understand more about this transition from warm and wet to dry and very cold.
A recent study based on data collected by one of the rover’s instruments suggests that Mars was actually moving back and forth between wetter and drier weather before it completely lost surface water about three billion years ago.
Curiosity has been steadily climbing Mount Sharp, 3 kilometers high, located in the center of Gale Crater, since 2014.
An instrument called the ChemCam is located on the rover’s mast and includes a high-resolution camera and a laser that can evaporate rocks to help the rover analyze their chemical composition. ChemCam has an infrared laser that can heat pieces of stone to 18,000 degrees Fahrenheit. This evaporates rocks and creates plasma, allowing scientists to essentially look inside the minerals and chemicals that make up rocks and peek back into the geological history of the planet.
A camera on the ChemCam was used to capture observations of Mount Sharp terrain, which reveals parts of Martian’s past as the rock changes.
A lesson in the history of Mars
Mount Sharp is an intriguing feature of Mars, as it is one of the best ways the red planet has recorded the history of its climate, water and sediments.
“The 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. These rock layers recorded these changes in great detail,” said Roger Wiens, a study associate. author at work and scientist of the ChemCam team from Los Alamos National Laboratory, in a statement.
The study was published last week in the journal Geology.
Orbits around Mars have previously recorded information about minerals within the slopes of Mount Sharp. Curiosity data provided even more detailed observations from sedimentary rock layers and revealed dry and wet periods of the planet’s past.
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Curiosity reveals great changes in the layers
As curiosity climbed Mount Sharp, the layers changed dramatically.
The foot of Mount Sharp is made of clay that has settled along the lake that once filled the crater. Above that are layers of sandstone that still preserve evidence of how they formed from wind-shaped dunes during the drier season. The layers above this reveal more deposits from the floodplain, indicating the return of wet conditions to Mars.
Observations of curiosity reveal that these changes between the wet and dry eras were large-scale events that alternated until the planet became permanently dry. Mount Sharp’s climate record allowed Curiosity to perfect itself in a time that stretched from 2.9 billion to 3.7 billion years ago.
As the rover continues its mission, Curiosity will continue to climb at the foot of Mount Sharp and use its drill to further explore the types of rocks and what they are discovering. This could provide more insight into the cause of such drastic climate fluctuations.
This story was first published on CNN.com, “Mars didn’t lose all its water at once, based on the discovery of the Curiosity rover.”