It might appear as a postcard from Arizona, but this snapshot shows something far more exotic: planet Mars, as seen by NASA’s Curiosity Rover.
The image may be a combination of 21 individual photographs the rover took recently to review a wierd type of wispy cloud over its Gale Crater home. Scientists realized 2 Earth years ago that the cloud type was forming earlier in Martian year than they expected. So this Martian year, Curiosity was looking for first clouds, and it had been not disappointed. The clouds did indeed show up beginning in late January, when the robotic skywatcher began documenting the wispy, ice-rich clouds scattering sunlight in sometimes-colorful displays.
“I always marvel at the colours that show up: reds and greens and blues and purples,” Mark Lemmon, an atmospheric scientist with the Space Science Institute in Colorado, said in NASA statement. “It’s really cool to ascertain something shining with many color on Mars.”
Strangely, these clouds appear higher within the Mars atmosphere than those clouds scientists typically see on planet, consistent with NASA. Usually, if a cloud passes over Curiosity, the structures are filled with water ice and float about 37 miles (60 kilometers) above the Martian surface.
The clouds in Curiosity’s new photos are higher within the atmosphere, although NASA didn’t specify their altitude. the differnce may reflect a special composition, clouds of frozen CO2 or dry ice, consistent with the agency, although the scientists aren’t yet confident therein explanation.
The clouds are at their prettiest just after sunset, when the last light makes the ice crystals glow, which is why scientists call them noctilucent, or night-shining. (Curiosity can monitor these noctilucent clouds with both its black-and-white navigation cameras and its color Mast Camera.)
Some of these clouds even appear a small iridescent when the cloud particles are very similar sizes, Lemmon said, which usually happens when clouds have just formed and have grown at an equivalent speed.