Having just celebrated its two-year anniversary on the Red Planet back in August, NASA’s Curiosity has rolled in another achievement: capturing images of Martian clouds.
Last week, @MarsCuriosity shared this photo (right) and tweeted: “Head for the hills! I'm driving towards these hills on Mars to do geology work & also search for clouds.”
During its first year, the rover fulfilled its goal of determining whether Mars had environmental conditions favorable for microbial life when it found sedimentary rocks containing clay, suggesting that a lakebed existed billions of years ago. Then, in its second year, Curiosity drove towards its long-term science destination on the lower slopes of Mount Sharp at the center of Gale Crater.
By turning its instruments skyward, the rover hopes to shed light on weather patterns that have helped shape the climate on Mars. “Clouds are part of the planet’s climate system,” Robert Haberle of NASA Ames tells Astrobiology Magazine. “Their behavior tells us about winds and temperatures.” Winds are the primary mechanism that shaped the planet’s surface for the past three to four billion years, he adds.
The wind-blown Martian clouds captured by Curiosity are probably composed of ice crystals and supercooled water droplets—yet another indication of ancient Martian life. “Some studies suggest that clouds in the past may have significantly warmed the planet through a greenhouse effect,” Haberle explains. “A warmer environment is more conducive to life.”
Correction: NASA's Opportunity took the cloud image above in 2006. https://twitter.com/MarsCuriosity/status/509123819835895809