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Observers on Mars can view transits of Phobos ... from the sidereal year. However, on Mars, this cycle is 43,000 Martian years (81,000 Earth years) rather than ...
Definition of year and seasons. The length of time for Mars to complete one orbit around the Sun in respect to the stars, its sidereal year, is about 686.98 Earth solar days (≈ 1.88 Earth years), or 668.5991 sols. Because of the eccentricity of Mars' orbit, the seasons are not of equal length.
Phobos is a small, irregularly shaped object with a mean radius of 11 km (7 mi). It orbits 6,000 km (3,700 mi) from the Martian surface, closer to its primary body than any other known natural satellite to a planet. It orbits Mars much faster than Mars rotates and completes an orbit in just 7 hours and 39 minutes.
Mars has an orbit with a semimajor axis of 1.524 astronomical units (228 million km) (12.673 light minutes), and an eccentricity of 0.0934. [1][2] The planet orbits the Sun in 687 days [3] and travels 9.55 AU in doing so, [4] making the average orbital speed 24 km/s. The eccentricity is greater than that of every other planet except Mercury ...
Orbit insertion. v. t. e. The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars.
Culmination. In observational astronomy, culmination is the passage of a celestial object (such as the Sun, the Moon, a planet, a star, constellation or a deep-sky object) across the observer's local meridian. [1] These events are also known as meridian transits, used in timekeeping and navigation, and measured precisely using a transit telescope.
The sidereal year is 20 min 24.5 s longer than the mean tropical year at J2000.0 (365.242 190 402 ephemeris days). [ 1 ] At present, the rate of axial precession corresponds to a period of 25,772 years, [ 3 ] so sidereal year is longer than tropical year by 1,224.5 seconds (20 min 24.5 s, ~365.24219*86400/25772).
Rotation period (astronomy) In astronomy, the rotation period or spin period[1] of a celestial object (e.g., star, planet, moon, asteroid) has two definitions. The first one corresponds to the sidereal rotation period (or sidereal day), i.e., the time that the object takes to complete a full rotation around its axis relative to the background ...