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Venus Planet


Solar System Explanation ::-- Sun|| Solar Planet || Mercury Planet || Jupitor Planet || Venus Planet || Earth Planet || Uranus Planet || Saturn Planet || Mars Planet || Neptune Planet || Dwarf Planet || Astroids || Comet ||


Facts about Planet Venus

* Diameter: 12,100 km. It is about 1040km smaller in diameter than Earth

* Temperature: Ranges from 900F+/- 50F (about 500°C +/- 32°C) at the surface

* Distance from Earth: At its closest, Venus is 41,840,000 km away

* Atmosphere: Carbon dioxide (95%), nitrogen, sulfuric acid, and traces of other elements

* Surface: A rocky, dusty, waterless expanse of mountains, canyons, and plains, with a 200-mile river of hardened lava

* Rotation of its axis: 243 Earth days (1 Venusian Day)

* Rotation around the Sun: 225 Earth days

* Magnetic Field: No

 

Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows. Because Venus is an inferior planet from Earth, it never appears to venture far from the Sun: its elongation reaches a maximum of 47.8°. Venus reaches its maximum brightness shortly before sunrise or shortly after sunset, for which reason it has been known as the Morning Star or Evening Star.

 

Venus is classified as a terrestrial planet and it is sometimes called Earth's "sister planet" due to the similar size, gravity, and bulk composition. Venus is covered with an opaque layer of highly reflective clouds of sulfuric acid, preventing its surface from being seen from space in visible light. Venus has the densest atmosphere of all the terrestrial planets in the Solar System, consisting mostly of carbon dioxide. Venus has no carbon cycle to lock carbon back into rocks and surface features, nor does it seem to have any organic life to absorb it in biomass. Venus is believed to have previously possessed Earth-like oceans, but these evaporated as the temperature rose. Venus's surface is a dusty dry desertscape with many slab-like rocks, periodically refreshed by volcanism. The water has most likely dissociated, and, because of the lack of a planetary magnetic field, the hydrogen has been swept into interplanetary space by the solar wind. The atmospheric pressure at the planet's surface is 92 times that of the Earth.



The Venusian surface was a subject of speculation until some of its secrets were revealed by planetary science in the twentieth century. It was finally mapped in detail by Project Magellan in 1990–91. The ground shows evidence of extensive volcanism, and the sulfur in the atmosphere may indicate that there have been some recent eruptions. The absence of evidence of lava flow accompanying any of the visible caldera remains an enigma. The planet has few impact craters, demonstrating that the surface is relatively young, approximately 300–600 million years old. There is no evidence for plate tectonics, possibly because its crust is too strong to subduct without water to make it less viscous. Instead, Venus may lose its internal heat in periodic major resurfacing events.

 

Venus (Greek: Aphrodite; Babylonian: Ishtar) is the goddess of love and beauty. The planet is so named probably because it is the brightest of the planets known to the ancients. (With a few exceptions, the surface features on Venus are named for female figures.)
Venus has been known since prehistoric times. It is the brightest object in the sky except for the Sun and the Moon. Like Mercury, it was popularly thought to be two separate bodies: Eosphorus as the morning star and Hesperus as the evening star, but the Greek astronomers knew better. (Venus's apparition as the morning star is also sometimes called Lucifer.)



Venus is sometimes regarded as Earth's sister planet. In some ways they are very similar:

  • Venus is only slightly smaller than Earth (95% of Earth's diameter, 80% of Earth's mass).
  • Both have few craters indicating relatively young surfaces.
  • Their densities and chemical compositions are similar.

Because of these similarities, it was thought that below its dense clouds Venus might be very Earthlike and might even have life. But, unfortunately, more detailed study of Venus reveals that in many important ways it is radically different from Earth. It may be the least hospitable place for life in the solar system.

Venus is the brightest object in the sky besides our Sun and the Moon. It is also known as the morning star because at sunrise it appears in the east and and evening star as it appears at sunset when it is in the west. It cannot be seen in the middle of the night.

A Venusian day is 243 Earth days and is longer than its year of 225 days. Oddly, Venus rotates from east to west (retrograde - opposite to that of earth). If you were on Venus, the Sun would rise in the west and set in the east.

Venus and Earth are close together in space and similar in size, which is the reason Venus is called Earth's sister planet.


venus planet

Venus Physical characteristics

Venus is one of the four solar terrestrial planets, meaning that, like the Earth, it is a rocky body. In size and mass, it is very similar to the Earth, and is often described as Earth's "sister" or "twin". The diameter of Venus is only 650 km less than the Earth's, and its mass is 81.5% of the Earth's. Conditions on the Venusian surface differ radically from those on Earth, due to its dense carbon dioxide atmosphere. The mass of the atmosphere of Venus is 96.5% carbon dioxide, with most of the remaining 3.5% being nitrogen.

Venus Geography

About 80% of the Venusian surface is covered by smooth volcanic plains, consisting of 70% plains with wrinkle ridges and 10% smooth or lobate plains. Two highland "continents" make up the rest of its surface area, one lying in the planet's northern hemisphere and the other just south of the equator. The northern continent is called Ishtar Terra, after Ishtar, the Babylonian goddess of love, and is about the size of Australia. Maxwell Montes, the highest mountain on Venus, lies on Ishtar Terra. Its peak is 11 km above the Venusian average surface elevation. The southern continent is called Aphrodite Terra, after the Greek goddess of love, and is the larger of the two highland regions at roughly the size of South America. A network of fractures and faults covers much of this area.

As well as the impact craters, mountains, and valleys commonly found on rocky planets, Venus has a number of unique surface features. Among these are flat-topped volcanic features called farra, which look somewhat like pancakes and range in size from 20–50 km across, and 100–1,000 m high; radial, star-like fracture systems called novae; features with both radial and concentric fractures resembling spider webs, known as arachnoids; and coronae, circular rings of fractures sometimes surrounded by a depression. These features are volcanic in origin.
Most Venusian surface features are named after historical and mythological women. Exceptions are Maxwell Montes, named after James Clerk Maxwell, and highland regions Alpha Regio, Beta Regio and Ovda Regio. The former three features were named before the current system was adopted by the International Astronomical Union, the body that oversees planetary nomenclature.
The longitudes of physical features on Venus are expressed relative to its prime meridian. The original prime meridian passed through the radar-bright spot at the center of the oval feature Eve, located south of Alpha Regio. After the Venera missions were completed, the prime meridian was redefined to pass through the central peak in the crater Ariadne.[30]

Venus Orbit and rotation

Venus orbits the Sun at an average distance of about 108 million kilometers (about 0.7 AU), and completes an orbit every 224.65 days. Although all planetary orbits are elliptical, Venus is the closest to circular, with an eccentricity of less than 0.01. When Venus lies between the Earth and the Sun, a position known as "inferior conjunction", it makes the closest approach to Earth of any planet, lying at an average distance of 41 million km during inferior conjunction. The planet reaches inferior conjunction every 584 days, on average. Due to the decreasing eccentricity of Earth, the minimum distances will become greater. From the year 1 to 5383, there are 526 approaches less than 40 million km; then there are none for about 60,200 years. During periods of greater eccentricity Venus can come as close as 38.2 million km.
All the planets of the Solar System orbit in a counter-clockwise direction as viewed from above the Sun's north pole: most planets also rotate counter-clockwise but Venus rotates clockwise (called "retrograde" rotation) once every 243 Earth days—by far the slowest rotation period of any major planet. The equator of the Venusian surface rotates at 6.5 km/h while on Earth rotation speed at the equator is about 1,670 km/h. A Venusian sidereal day thus lasts longer than a Venusian year (243 versus 224.7 Earth days). Because of the retrograde rotation the length of a solar day on Venus is significantly shorter than the sidereal day. As a result of Venus's relatively long solar day, one Venusian year is about 1.92 Venusian days long. To an observer on the surface of Venus the Sun would appear to rise in the west and set in the east and the time from one sunrise to the next would be 116.75 Earth days (making the Venusian solar day shorter than Mercury's 176 Earth days).
Venus may have formed from the solar nebula with a different rotation period and obliquity, reaching to its current state because of chaotic spin changes caused by planetary perturbations and tidal effects on its dense atmosphere, a change that would have occurred over the course of billions of years. The rotation period of Venus may represent an equilibrium state between tidal locking to the Sun's gravitation, which tends to slow rotation, and an atmospheric tide created by solar heating of the thick Venusian atmosphere. A curious aspect of the Venusian orbit and rotation periods is that the 584-day average interval between successive close approaches to the Earth is almost exactly equal to five Venusian solar days. Whether this relationship arose by chance or is the result of tidal locking with the Earth is unknown.
Venus currently has no natural satellite, though the asteroid 2002 VE68 presently maintains a quasi-orbital relationship with it. In the 17th century Giovanni Cassini reported a moon orbiting Venus which was named Neith and there were numerous reported sightings over the following 200 years but it was ultimately determined that most were stars in the vicinity. Alex Alemi's and David Stevenson's 2006 study of models of the early Solar System at the California Institute of Technology shows that it is likely that billions of years ago Venus had at least one moon created by a huge impact event. About 10 million years later, according to the study, another impact reversed the planet's spin direction and caused the Venusian moon gradually to spiral inwarduntil it collided and merged with Venus. If later impacts created moons these also were absorbed in the same way. An alternative explanation for the lack of satellites is the effect of strong solar tides, which can destabilize large satellites orbiting the inner terrestrial planets.

 

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