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
Mars Cube One Mars Cube One Mars Cube One (or MarCO) is a Mars flyby mission that was launched on 5 May 2018 alongside NASA's "InSight" Mars lander mission. It consists of two nanospacecraft, MarCO-A and MarCO-B, that were able to provide a real-time communications link to Earth for "InSight" during its entry, descent, and landing (EDL) on 26 November 2018 - when "InSight" was out of line of sight from the Earth. Both are of the 6U CubeSat format, and the mission is a test of new miniaturized communications and navigation technologies. These are the first CubeSats designed to operate beyond Earth