Venus

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  • Venus
definition
  • The second planet from the sun in our solar system.
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Abstract from DBPedia
    Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never far from the Sun, either as morning star or evening star. Aside from the Sun and Moon, Venus is the brightest natural object in Earth's sky, capable of casting visible shadows on Earth at dark conditions and being visible to the naked eye in broad daylight. Venus is the second largest terrestrial object of the Solar System. It has a surface gravity slightly lower than on Earth and has a very weak induced magnetosphere. The atmosphere of Venus, mainly consists of carbon dioxide, and is the densest and hottest of the four terrestrial planets at the surface. With an atmospheric pressure at the planet's surface of about 92 times the sea level pressure of Earth and a mean temperature of 737 K (464 °C; 867 °F), the carbon dioxide gas at Venus's surface is in the supercritical phase of matter. Venus is shrouded by an opaque layer of highly reflective clouds of sulfuric acid, making it the planet with the highest albedo in the Solar System. It may have had water oceans in the past, but after these evaporated the temperature rose under a runaway greenhouse effect. The possibility of life on Venus has long been a topic of speculation but convincing evidence has yet to be found. Like Mercury, Venus does not have any moons. Solar days on Venus, with a length of 117 Earth days, are just about half as long as its solar year, orbiting the Sun every 224.7 Earth days. This Venusian daylength is a product of it rotating against its orbital motion, halving its full sidereal rotation period of 243 Earth days, the longest of all the Solar System planets. Venus and Uranus are the only planets with such a retrograde rotation, making the Sun move in their skies from their western horizon to their eastern. The orbit of Venus around the Sun is the closest to Earth's orbit, allowing them to approach each other at inferior conjunction closer than any other planet, at a synodic period of 1.6 years, while Mercury approaches them more often the closest. The close orbit of Venus and Earth furthermore results in the lowest gravitational potential difference and lowest delta-v needed to transfer from them to any other planet. This has made Venus a prime target for early interplanetary exploration. It was the first planet beyond Earth spacecrafts were sent to, starting with Venera 1 in 1961, and the first planet to be reached, impacted and in 1970 successfully landed on by Venera 7. As one of the brightest objects in the sky, Venus has been a major fixture in human culture for as long as records have existed. It has been made sacred to gods of many cultures, gaining its mainly used name from the Roman goddess of love and beauty which it is associated with. Furthermore it has been a prime inspiration for writers, poets and scholars. Venus was the first planet to have its motions plotted across the sky, as early as the second millennium BCE. Plans for better exploration with rovers or atmospheric missions, potentially crewed, at levels with almost Earth-like conditions have been proposed.

    金星(きんせい、ラテン語: Venus 、英語: Venus )は、太陽系で太陽に近い方から2番目の惑星。また、地球にもっとも近い公転軌道を持つ惑星である。 地球型惑星であり、太陽系内で大きさと平均密度がもっとも地球に似た惑星であるため、「地球の姉妹惑星」と表現されることがある。また、太陽系の惑星の中で最も真円に近い公転軌道を持っている。地球から見ると、金星は明け方と夕方にのみ観測でき、太陽、月に次いで明るく見える星であることから、明け方に見えるものを「明けの明星」、夕方に見えるものを「宵の明星」という。

    (Source: http://dbpedia.org/resource/Venus)