These are two separate videos taken by the Curiosity lander on Mars. They show one of the two moons of Mars, Phobos, transiting the sun.
|Curiosity sees a Phobos transit, sol 713|
Above, Curiosity watched on sol 713 as jagged Phobos passed across the face of the Sun. There are 84 images in this animation, which runs faster than natural speed. A couple of sunspots are faintly visible. The animation is composed of raw JPEG images, so contains artifacts, particularly at the high-contrast areas at the edges of the Sun and Phobos.
|Curiosity sees a Phobos transit, sol 369|
Curiosity watched Phobos pass across the Sun on sol 369, shooting one photo per second. This animation runs about 10 times natural speed.
Phobos is an itty bitty little thing, but it orbits very close to Mars, much closer than our Moon does to earth. Due to that, the apparent size of Phobos changes depending upon how close to the horizon, or how directly overhead, it is. It is the same phenomenon as a Harvest Moon. Thus, it appears larger in the second animation, which must have been taken close to the horizon.