Mars alternated between long dry spells and wetter eras before drying up completely into the near-dead world we see today, about three billion years ago, research shows.
Data collected by the NASA Curiosity rover, which has been on Mars since 2012, was used by researchers at the Research Institute in Astrophysics and Planetology.
Curiosity explores the base of Aeolis Mons, a mountain several miles high in the center of the Gale Crater, and the researchers used a telescope on the vehicle to make detailed observations of the steep terrain at a distance.
Using the ChemCam instrument, they discovered that the climate on Mars alternated between dry and wet periods, before completely drying up about 3 billion years ago.
View of hills on the slopes of Mount Sharp, showing the different types of terrain soon to be explored by the Curiosity rover, and the ancient environments in which they originated, according to the sedimentary structures observed in ChemCam’s telescope images
When Mars went dry, Earth may have been a water world, according to previous studies, and Venus may have had the perfect environment for life to thrive.
While Venus suffered from a runaway greenhouse effect that created the hellish world we see today, and Earth became a thriving continental planet, Mars remained dry.
Spacecraft orbiting Mars had already provided clues as to the mineral composition of the slopes of the 18,000-foot mountain, also known as Mount Sharp.
But now ChemCam has successfully made detailed observations of the sedimentary beds from the planet’s surface.
The instrument consists of a laser, camera and spectrograph that work together to remotely identify the chemical and mineral compositions of rocks.
Using this ‘telescope’, the team of American and French scientists was able to reveal the conditions under which these sedimentary beds were first formed.
Moving onto the terrain, which is several hundred meters thick, radically changes the types of beds, the team explained.
Lying above the lake-deposited clays that form the basis of Mount Sharp, wide, tall structures with transverse beds are a sign of the migration of wind-formed dunes.
These dunes are said to have formed during a long, dry climate period, which was thought to be common and which traversed shorter, wet periods.
Mars alternated between long dry spells and wetter eras before drying up completely into the near-dead world we see today, about three billion years ago, research shows.
Higher up the slope, researchers found thin alternating brittle and resistant beds, which were typical of floodplain river deposits.
These mark the return of wetter conditions, likely the result of flooding in the Gale Crater where Curiosity is investigating.
The climate of Mars therefore underwent several large-scale fluctuations between arid conditions and river and lake environments, the team revealed.
This happened until the generally arid conditions observed today joined in about three billion years ago – when the Earth was largely made up of water.
These mark the return of wetter conditions, likely the result of flooding in the Gale crater where Curiosity is investigating
During its extended mission on Mars, Curiosity is scheduled to climb the foothills of Mount Sharp and drill into the various beds to better understand their composition.
During these climbs and drilling episodes, Curiosity will test this model of shifts between wetter and dry periods on the Red Planet.
These periods characterize in more detail how the ancient climate evolved, and by drilling more through Curiosity, we may understand the origins of these large fluctuations, the team said.
The findings are published in the journal Geology.
NASA MARS CURIOSITY ROVER LAUNCHED IN 2011 AND HAS IMPROVED OUR UNDERSTANDING OF THE RED PLANET
The Mars Curiosity rover was initially launched from Cape Canaveral, a United States Air Force station in Florida on November 26, 2011.
After embarking on a 350 million mile (560 million km) journey, the £ 1.8 billion ($ 2.5 billion) research vehicle landed just 1.5 miles from its intended landing site.
After a successful landing on August 6, 2012, the rover traveled approximately 18 km.
It was launched on the Mars Science Laboratory (MSL) spacecraft, and the rover made up 23 percent of the mass of the total mission.
With 80 kg (180 lb) of scientific instruments on board, the rover weighs a total of 899 kg (1,982 lb) and is powered by a plutonium fuel source.
The rover is 2.9 meters long, 2.7 meters wide and 2.2 meters high.
The Mars curiosity rover was originally intended as a two-year mission to gather information to help answer the question of whether the planet could support life, have liquid water, study the climate and geology of Mars and have spent more than 2,000 days since then is active.
The rover was initially intended as a two-year mission to gather information to help answer the question of whether the planet can support life, have liquid water, and study the climate and geology of Mars.
Due to its success, the mission has been extended indefinitely and has now been active for more than 2,000 days.
The rover has several scientific instruments on board, including the mastcam which consists of two cameras and can take high-resolution images and videos in real color.
So far on the robot’s journey the size of a car he has encountered an ancient stream bed where liquid water used to flow, not long after he also discovered that billions of years ago a nearby area known as Yellowknife Bay was part of a lake that could have sustained microbial life.