phobos and demos are natural satellite of which planet
Phobos (moon) Phobos (/ˈfoʊbəs/ FOH-bəs or /ˈfoʊbɒs/ FOH-bos,[4] from the Greek Φόβος.) (systematic designation: Mars I) is the innermost and larger of the two natural satellites of Mars,[5] the other being Deimos. Both moons were discovered in 1877 by American astronomer Asaph Hall.
Satellite In 1957 the Soviet Union launched the world's first artificial satellite, Sputnik 1. Since then, about 6,600 satellites from more than 40 countries have been launched. According to a 2013 estimate, 3,600 remained in orbit.[1] Of those, about 1,000 were operational;[2] while the rest have lived out their useful lives and become space debris. Approximately 500 operational satellites are in low-Earth orbit, 50 are in medium-Earth orbit (at 20,000 km), and the rest are in geostationary orbit (at 36,000 km).[3] A few large satellites have been launched in parts and assembled in orbit. Over a dozen space probes have been placed into orbit around other bodies and become artificial satellites to the Moon, Mercury, Venus, Mars, Jupiter, Saturn, a few asteroids,[4] a comet and the Sun.