<ul><li>The European Space Agency (ESA) released images from its Mars Express orbiter showing Mars' moons, Phobos and Deimos, as Phobos crosses in front of Deimos.</li><li>Phobos and Deimos are Mars' potato-shaped moons, likely captured asteroids from the nearby main asteroid belt. Phobos is larger, but still significantly smaller than Earth's moon, while Deimos is smaller and has a thick layer of dust on its surface.</li><li>The animation provided by Andrea Luck shows the occultation of Phobos crossing in front of Deimos, providing an example of this astronomical event.</li><li>Phobos circles Mars three times a day and is gradually getting closer to the planet, with a potential future of crashing into it or shredding into a ring.</li></ul>

Watch as Mars’ moons trade places in the sky

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