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Representation of Venus (yellow) and Earth (blue) circling around the Sun. Venus and its rotation in respect to its revolution. Venus has an orbit with a semi-major axis of 0.723 au (108,200,000 km; 67,200,000 mi), and an eccentricity of 0.007.
Venus reaches its greatest magnitude of about −4.5 when it is an intermediate crescent shape at the point in its orbit, when it is 68 million km away from the Earth, at which point the illuminated part of its disk reaches its greatest angular area as seen from the Earth (a combination of its closeness and the fact that it is 28% illuminated). [2]
Plot of the changing orbital eccentricities of Mercury, Venus, Earth and Mars over the next 50 000 years. The arrows indicate the different scales used, as the eccentricities of Mercury and Mars are much greater than those of Venus and Earth. The 0 point on x-axis in this plot is the year 2007.
The equant point (shown in the diagram by the large • ), is placed so that it is directly opposite to Earth from the deferent's center, known as the eccentric (represented by the × ). A planet or the center of an epicycle (a smaller circle carrying the planet) was conceived to move at a constant angular speed with respect to the equant.
The planetary orbit is a circle with epicycles. The Sun is approximately at the center of the orbit. The speed of the planet in the main orbit is constant. Despite being correct in saying that the planets revolved around the Sun, Copernicus was incorrect in defining their orbits.
In the Hipparchian, Ptolemaic, and Copernican systems of astronomy, the epicycle (from Ancient Greek ἐπίκυκλος (epíkuklos) 'upon the circle', meaning "circle moving on another circle") [1] was a geometric model used to explain the variations in speed and direction of the apparent motion of the Moon, Sun, and planets.
Venus currently has a surface temperature of 450℃ (the temperature of an oven’s self-cleaning cycle) and an atmosphere dominated by carbon dioxide (96%) with a density 90 times that of Earth’s.
Overall, Venus has several times as many volcanoes as Earth, and it possesses some 167 giant volcanoes that are over 100 kilometres (62 mi) across. The only volcanic complex of this size on Earth is the Big Island of Hawaii. However, this is not because Venus is more volcanically active than Earth, but because its crust is older.