text: An areostationary orbit, areosynchronous equatorial orbit (AEO), or Mars geostationary orbit is a circular areo­synchronous orbit (ASO) approximately  in altitude above the Mars equator and following the direction of Mars's rotation.
  An object in such an orbit has an orbital period equal to Mars's rotational period, and so to ground observers it appears motionless in a fixed position in the sky. It is the Martian analog of a Geostationary orbit (GEO). 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.
  Although it would allow for uninterrupted communication and observation of the Martian surface, no artificial satellites have been placed in this orbit due to the technical complexity of achieving and maintaining one.
  Characteristics
  The radius of an areostationary orbit can be calculated using Kepler's Third Law.
  Where:
  Substituting the mass of Mars for M and the Martian sidereal day for T and solving for the semimajor axis yields a synchronous orbit radius of  above the surface of the Mars equator. Subtracting Mars's radius gives an orbital altitude of .
  Two stable longitudes exist - 17.92°W and 167.83°E. Satellites placed at any other longitude will tend to drift to these stable longitudes over time.