Extraterrestrial skies Mars appears to be the angular diameter as seen from Earth (0.35°), and sends 40% of the light, approximately the brightness of a slightly cloudy afternoon on Earth. On June 3, 2014, the "Curiosity" rover on Mars observed the planet Mercury transiting the Sun, marking the first time a planetary transit has been observed from a celestial body besides Earth. Mars has two small moons: Phobos and Deimos. From the Martian surface, Phobos has one-third to one-half the angular diameter of the Sun while Deimos is barely more than a dot (only 2′ angular diameter). The orbital period of Phobos
Flag of Mars "red Mars and two moons in blue field above a diagonal, white below". In Robert A. Heinlein's 1961 science-fiction novel "Stranger in a Strange Land", a flag of Mars is hastily improvised, consisting of "the field in white and the sigil of Mars in red". In The Expanse television series, based on "The Expanse" series of novels by James S. A. Corey, the Martian Congressional Republic is the governing body that rules over the inhabitants of Mars and is one of the two human superpowers in the series. Its flag is reminiscent of Mars and its two moons, Phobos and