NASA’s Curiosity Rover has captured the clearest look at clouds moving across the Martian sky yet.
In new sequences captured by Curiosity, wispy, early-season clouds that resemble Earth’s cirrus clouds can be seen.
The footage was taken during an early morning last month.
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NASA is saying ‘these clouds are the most clearly visible so far.’
Researchers used the probe’s Navigation Camera (Navcam) to capture them.
One set of images was taken with the camera pointed straight up, and for the other, it was pointed just above the southern horizon.
NASA says it’s early to spot the clouds.
In previous observances, clouds in the Martian sky would appear near the equator when it was farthest from the sun, which is two months from now.
While clouds moving in the Martian sky have been observed previously by Curiosity and other missions on the Mars surface (including NASA’s Phoenix Mars Lander in the Martian arctic nine years ago), NASA says ‘these clouds are the most clearly visible so far.’
Researchers used the probe’s Navigation Camera (Navcam) to take two sets of eight images of the sky on an early morning last month.
For the first set, the camera pointed nearly straight up.
In the second set, the camera pointed just above the southern horizon.
Both recorded cloud movement, while a look at the sky taken later that same afternoon showed no clouds.
‘It is likely that the clouds are composed of crystals of water ice that condense out onto dust grains where it is cold in the atmosphere,’ said Curiosity science-team member John Moores of York University, Toronto, Canada, in the NASA announcement.
‘The wisps are created as those crystals fall and evaporate in patterns known as “fall streaks” or “mare’s tails.”‘
‘While the rover does not have a way to ascertain the altitude of these clouds, on Earth such clouds form at high altitude.’
The clouds’ appearance is relatively early in Mars’ revolution around the sun, which is an elliptical orbit that brings the planet to varying distances from the star.
In previous observances, clouds in the Martian sky would appear near the planet’s equator when it was farthest from the sun.
These new images were taken about two months before that point.
The enhanced-image sequences were created by generating an ‘average’ of all the frames in each sequence, subtracting that average from each frame and then emphasizing any frame-to-frame changes.
In the raw images, the moving clouds are also visible, though fainter.