article_snippet: This spectacular image reveals Phobos, one of the two moons orbiting Mars (the other is Deimos), silhouetted against the Martian surface (shown).
article_snippet: Although the moon Phobos against the planet is the larger of the two moons, it is still only about 14 miles (22km) across, and completes an orbit of Mars once every seven Earth hours.
article_snippet: An equally spectacular image reveals Phobos, one of the two moons orbiting Mars (the other is Deimos), silhouetted against the Martian surface.
article_snippet: Although Phobos is the larger of the two moons, it is still only about 14 miles (22km) across, and completes an orbit of Mars once every seven Earth hours.