The Curiosity rover had an eye to the sky on 1 Aug 2013 and caught an eclipse of sorts.
The Mastcam instrument took a series of images of the Martian moon Phobos passing directly in front of the other Martian moon, Deimos.
In the press release from NASA/JPL (below), the apparent size of the moons is compared to how we see our moon so and NASA included a pictoral comparison>/a>.
The NASA press release:
PASADENA, Calif. — The larger of the two moons of Mars, Phobos, passes directly in front of the other, Deimos, in a new series of sky-watching images from NASA’s Mars rover Curiosity.
Large craters on Phobos are clearly visible in these images from the surface of Mars. No previous images from missions on the surface caught one moon eclipsing the other.