Because Curiosity doesn't have anything else to Instagram, it just took the clearest images of a solar eclipse from the surface of Mars. The picture is clearer than those taken by humans!

The moon above, (taken on August 17) is Mar's largest moon, Phobos. It was in the midst of an annular solar eclipse. 

According to Mark Lemmon of Texas A&M University and co-investigator of Curiosity's MastCam, this is the closest anyone on Mars will ever get to a total eclipse.
This one is by far the most detailed image of any Martian lunar transit ever taken, and it is especially useful because it is annular. It was even closer to the sun’s center than predicted, so we learned something.
[NASA via]