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  2. Orbit of Mars - Wikipedia

    en.wikipedia.org/wiki/Orbit_of_Mars

    Extra-close oppositions of Mars happen every 15 to 17 years, when we pass between Mars and the Sun around the time of its perihelion (closest point to the Sun in orbit). The minimum distance between Earth and Mars has been declining over the years, and in 2003 the minimum distance was 55.76 million km, nearer than any such encounter in almost ...

  3. List of Solar System objects by size - Wikipedia

    en.wikipedia.org/wiki/List_of_Solar_System...

    The size of solid bodies does not include an object's atmosphere. For example, Titan looks bigger than Ganymede, but its solid body is smaller. For the giant planets , the "radius" is defined as the distance from the center at which the atmosphere reaches 1 bar of atmospheric pressure.

  4. List of Mars orbiters - Wikipedia

    en.wikipedia.org/wiki/List_of_Mars_orbiters

    Artist's rendition of Mars Express as seen by NASA's Mars Global Surveyor Image of Mars Express in orbit at Mars. 2001 Mars Odyssey was launched April 7, 2001 on a Delta II rocket and currently holds the record for the longest-surviving continually active spacecraft in orbit around a planet other than Earth at 23 years, 3 months and 7 days.

  5. Mars - Wikipedia

    en.wikipedia.org/wiki/Mars

    Mars has two relatively small (compared to Earth's) natural moons, Phobos (about 22 kilometres (14 mi) in diameter) and Deimos (about 12 kilometres (7.5 mi) in diameter), which orbit close to the planet. The origin of both moons is unclear, although a popular theory states that they were asteroids captured into Martian orbit.

  6. Areostationary orbit - Wikipedia

    en.wikipedia.org/wiki/Areostationary_orbit

    An areostationary orbit, areosynchronous equatorial orbit (AEO), or Mars geostationary orbit is a circular areo­synchronous orbit (ASO) approximately 17,032 km (10,583 mi) 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 ...

  7. 5261 Eureka - Wikipedia

    en.wikipedia.org/wiki/5261_Eureka

    5261 Eureka is the first Mars trojan discovered. [5] It was discovered by David H. Levy and Henry Holt at Palomar Observatory on 20 June 1990. [1] It trails Mars (at the L 5 point) at a distance varying by only 0.3 AU during each revolution (with a secular trend superimposed, changing the distance from 1.5–1.8 AU around 1850 to 1.3–1.6 AU around 2400).

  8. Areosynchronous orbit - Wikipedia

    en.wikipedia.org/wiki/Areosynchronous_orbit

    The orbital altitude required to maintain an areosynchronous orbit is approximately 17,000 kilometres (11,000 mi). If a satellite in areosynchronous orbit were to be used as a communication relay link, it "would experience communications ranges of 17,000 to 20,000 kilometres (11,000 to 12,000 mi)" to various points on the visible Martian surface.

  9. History of Mars observation - Wikipedia

    en.wikipedia.org/wiki/History_of_Mars_observation

    The size of this primary lens is the main factor in determining the light gathering ability and resolution of a refracting telescope. [41] [42] During the opposition of Mars in 1830, the German astronomers Johann Heinrich Mädler and Wilhelm Beer used a 95 mm (3.7 in) Fraunhofer refracting telescope to launch