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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 ...
[1] [2] The low eccentricity and comparatively small size of its orbit give Venus the least range in distance between perihelion and aphelion of the planets: 1.46 million km. The planet orbits the Sun once every 225 days [ 3 ] and travels 4.54 au (679,000,000 km; 422,000,000 mi) in doing so, [ 4 ] giving an average orbital speed of 35 km/s ...
For instance, for completing an orbit every 24 hours around a mass of 100 kg, a small body has to orbit at a distance of 1.08 meters from the central body's center of mass. In the special case of perfectly circular orbits, the semimajor axis a is equal to the radius of the orbit, and the orbital velocity is constant and equal to
It takes 224.7 Earth days for Venus to complete an orbit around the Sun, and a Venusian solar year is just under two Venusian days long. The orbits of Venus and Earth are the closest between any two Solar System planets, approaching each other in synodic periods of 1.6 years.
Mars hosts many enormous extinct volcanoes (the tallest is Olympus Mons, 21.9 km or 13.6 mi tall) and one of the largest canyons in the Solar System (Valles Marineris, 4,000 km or 2,500 mi long). Geologically, the planet is fairly active with marsquakes trembling underneath the ground, dust devils sweeping across the landscape, and cirrus clouds.
The orbit of Venus is 224.7 Earth days (7.4 avg. Earth months [30.4 days]). The phases of Venus result from the planet's orbit around the Sun inside the Earth's orbit giving the telescopic observer a sequence of progressive lighting similar in appearance to the Moon's phases. It presents a full image when it is on the opposite side of the Sun.
Horrocks corrected Kepler's calculation for the orbit of Venus, realized that transits of Venus would occur in pairs 8 years apart, and so predicted the transit of 1639. [11] Although he was uncertain of the exact time, he calculated that the transit was to begin at approximately 15:00.
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.