A "Voyager" type spacecraft with a Golden Record but with contents depicting a civilization of Cats in Mars, and the Space Craft + Golden Record are made from materials from Mars. Put this in orbit around Mars, and have it emit a signal on loop with an Arecibo Message depicting the Cat Civilization.
The scientific community would just collapse and we'd be worshipping cats as a world wide religion.
๐ธ
-Sincerely, totally not a cat