Phobos (mythology) of Cypselus on the shield of Agamemnon. American astronomer Asaph Hall named a satellite of the planet Mars, "Phobos", which he discovered along with the second Mars satellite, "Deimos", in 1877. Phobos is the larger of the two satellites. The word "phobia" derives from "phobos", (Φόβος), meaning fear. The two brothers Deimos and Phobos were particularly worshipped in the city state of "Sparta" as they were the sons of Ares, the god of war. Phobos in Greek literally means "fear" (). Spartan soldiers would idolize Phobos, because he symbolized discipline, and consistency of the armed forces. Because Phobos and Deimos
Phobos (moon) on Greek mythology, in which Phobos is a companion to the god Ares. Phobos has dimensions of , and retains too little mass to be rounded under its own gravity. Phobos does not have an atmosphere due to its low mass and low gravity. It is one of the least reflective bodies in the Solar System, with an albedo of about 0.071. Infrared spectra show that it has carbon-rich material found in carbonaceous chondrites. Instead, its composition shows similarities to that of Mars’ surface. Phobos's density is too low to be solid rock, and it is known to have significant