By Alvin Alexander. Last updated: March 23, 2017
From this story on sciencemag.org:
“NASA’s Curiosity rover usually keeps its instruments firmly focused on Mars’s ground, zapping grit with its laser or drilling cores in bedrock. But every few days, the SUV-sized robot, like any good dreamer, shifts its sights upward to the clouds. Well into its fifth year, the rover has now shot more than 500 movies of the clouds above it, including the first ground-based view of martian clouds shaped by gravity waves ...”
(See the story for more information, and some animations which unfortunately just keep endlessly repeating.)