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Every opposition has some significance because Mars is visible from Earth all night, high and fully lit, but the ones of special interest happen when Mars is near perihelion, because this is when Mars is also nearest to Earth. One perihelic opposition is followed by another either 15 or 17 years later. In fact every opposition is followed by a ...
The maximum angular separation of the Earth and Moon varies considerably according to the relative distance between the Earth and Mars: it is about 25′ when Earth is closest to Mars (near inferior conjunction) but only about 3.5′ when the Earth is farthest from Mars (near superior conjunction). For comparison, the apparent diameter of the ...
In gravitationally bound systems, the orbital speed of an astronomical body or object (e.g. planet, moon, artificial satellite, spacecraft, or star) is the speed at which it orbits around either the barycenter (the combined center of mass) or, if one body is much more massive than the other bodies of the system combined, its speed relative to the center of mass of the most massive body.
Several factors make placing a spacecraft into an areostationary orbit more difficult than a geostationary orbit. Since the areostationary orbit lies between Mars's two natural satellites, Phobos (semi-major axis: 9,376 km) and Deimos (semi-major axis: 23,463 km), any satellites in the orbit will suffer increased orbital station keeping costs due to unwanted orbital resonance effects.
Valles Marineris (/ ˈ v æ l ɪ s m ær ɪ ˈ n ɛər ɪ s /; [1] Latin for Mariner Valleys, named after the Mariner 9 Mars orbiter of 1971–72 which discovered it) is a system of canyons that runs along the Martian surface east of the Tharsis region. [2]
The mystery of Mars's interior has been revealed thanks to marsquakes. Using data compiled by NASA's InSight mission that has detected hundreds of marsquakes since landing on the red planet in ...
A satellite in areosynchronous orbit does not necessarily maintain a fixed position in the sky as seen by an observer on the surface of Mars; however, such a satellite will return to the same apparent position every Martian day. The orbital altitude required to maintain an areosynchronous orbit is approximately 17,000 kilometres (11,000 mi).
The orbit of Mars (yellow band; varies between 1.381 and 1.666 AU) displayed with 6 theoretically possible orbits for an asteroid (red line). The orbit of a Mars-crosser is displayed in the bottom row on the right. In generic terms, a Mars-crosser has a smaller perihelion and a larger aphelion compared to Mars.