It’s over 6 years since NASA’s Curiosity Rover made Mars it's home in an expedition to unravel the Red Planet’s mysteries: if it is, or was, suitable for life. Since landing on the planet in 2012, the car-sized rover has helped astronomers to answer lots of questions about the CO2 rich world and also provided clues of extraterrestrial life.

NASA Rover Clouds Curiosity Rover

NASA's Curiosity Mars Rover Finds a Clay Cache
NASA's Curiosity Mars rover took this selfie on May 12, 2019 (the 2,405th Martian day, or sol, of the mission). To the lower-left of the rover are its two recent drill holes, at targets called "Aberlady" and "Kilmarie."Credit: NASA/JPL-Caltech/MSSS

On May 7 and May 12, Curiosity Rover took its mission to a different level. It sat back and watched Mars’ atmosphere. Using its black-and-white Navigation Cameras (Navcams), the rover took images of drifting clouds during the said period (sols 2400 and 2405). The Marian clouds, which drift 19 miles (31 kilometers) above the planet’s surface, are “likely water-ice clouds,” NASA wrote, and they look so much like Earth’s cirrus clouds.

NASA Mars Clouds Curiosity Rover

These are likely water-ice clouds about 19 miles (31 kilometers) above the surface. They are also "noctilucent" clouds, meaning they are so high that they are still illuminated by the Sun, even when it's night at Mars' surface. Scientists can watch when light leaves the clouds and use this information to infer their altitude. (Source: NASA)

The composition of Martian clouds may have strong similarities with that of Earth, at least visually. However, Mars’ atmosphere is vastly different. The air on Earth is 100 times thicker than Mars’. Unlike our home plant which is dominated by nitrogen (77%) and oxygen (21%), the red planet comprises of mostly carbon dioxide (95%), with a very small amount of oxygen (0.13%).

The video clips of Mars’ atmosphere recorded by Curiosity Rover will help scientists in their quest to better understand the planet’s atmospheric dynamics. The clips are currently being compared to observations of Mar’s skies by NASA’s InSight lander – a robot currently investigating the Red Planet’s interior some 373 miles away from Curiosity.

Mars NASA Clouds Curiosity Rover

(Source: NASA)

Clips of the Martian clouds captured from two vantage points will help scientists in calculating their altitude, NASA wrote.

Curiosity Rover uncovers minerals usually associated with water

Having completed exploration on the Aeolis Palus in the Gale Crater where it landed on August 6, 2012, the Curiosity Rover is at the moment studying the “clay-bearing unit,” according to NASA’s description, where it has allegedly found the highest amount of clay minerals since the mission began. The rover drilled on two rock targets referred to as "Aberlady" and "Kilmarie" to find minerals usually associated with liquid water. Hence, discovering a large amount of it within that region may indicate that the area used to be habitable.

NASA Clouds Mars Curiosity Rover

(Source: NASA)

“What these new findings mean for the region is still up for debate,” NASA wrote. “It's likely that the rocks in the area formed as layers of mud in ancient lakes. Water interacted with sediment over time, leaving an abundance of clay in the rocks there."

NASA is, however, planning to send another robot to study the Red Planet in 2020. The rover is scheduled to launch in July 2020, from Florida’s Cape Canaveral Air Force Station. NASA is targeting to land the rover on the Jezero Crater, Mars.