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An areostationary orbit (abbreviated ASO) is a circular areosynchronous orbit in the Martian equatorial plane about above the surface, any point on which revolves about Mars in the same direction and with the same period as the Martian surface. Areostationary orbit is a concept similar to Earth's geostationary orbit. The prefix ''areo-'' derives from Ares, the ancient Greek god of war and counterpart to the Roman god Mars, with whom the planet was identified. The modern Greek word for Mars is ''Άρης'' (Áris). To date, no artificial satellites have been placed in this orbit, but it is of interest to some scientists foreseeing a future telecommunications network for the exploration of Mars.〔 〕 The proposed Mars One mission includes a communications system featuring amongst others things an areostationary satellite. An asteroid or station placed in areostationary orbit could also be used to construct a Martian space elevator for use in transfers between the surface of Mars and orbit. == Formula == Orbital speed (how fast a satellite is moving through space) is calculated by multiplying the angular speed of the satellite by the orbital radius: : By this formula we can find the geostationary-type orbit of an object in relation to Mars (this type of orbit above is referred to as an areostationary orbit if it is above Mars). The areogeocentric gravitational constant GM (which is μ) for Mars has the value of 42,828 km3s−2, and the known rotational period (''T'') of Mars is 88,642.66 seconds. Since ω = 2π/''T'', using the formula above, the value of ω is found to be approx 7.088218×10−5 s−1. Thus, ''r''3 = 8.5243×1012 km3, whose cube root is 20,427 km; subtracting the equatorial radius of Mars (3396.2 km) we have 17,031 km. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「areostationary orbit」の詳細全文を読む スポンサード リンク
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