THE PLANET VENUS

VENUS is the second closest planet from the Sun after Mercury. The planet orbits the Sun for 224.7 Earth days. Venus has no natural satellite and is named after the goddess of love and beauty in Roman mythology. After the Moon, the planet is the brightest natural object in the night sky, with a visible magnitude of -4.6 which is bright enough to produce a shadow. Venus is an inferior planet with an elongation angle of 47.8 °. The maximum brightness of the planet can be seen immediately before sunrise or after sunset, so it is called the Morning Star or the Twilight Star.Venus is a terrestrial planet and is sometimes called the Earth's "planet Earth" because of its size, gravity, and similar compositions (Venus is the closest planet from Earth and the closest planet to Earth). However, in another case the planet is very different from Earth. The planet has the densest atmosphere among four Earth planets comprising 96% carbon dioxide. Venus's surface atmospheric pressure is 92 times larger than Earth's. With an average surface temperature of 735 K (462 ° C; 863 ° F), Venus is the hottest planet in the Solar System. The planet does not have a carbon cycle that traps carbon in rocks and surface appearance, nor does it have organic life that can absorb carbon in the form of biomass. Venus is enveloped by an opaque layer of highly reflective sulfuric acid clouds, so the surface can not be seen from outer space. Venus may have once had an ocean, but the ocean evaporated due to an increase in temperature caused by the effects of a greenhouse. Much of the water may have been biodegradable, and the solar wind has made free hydrogen undergoing outer space as a result of the absence of an internal magnetic field on Venus. The surface of Venus itself is descending, dry, and interspersed by rocks that are periodically updated by volcanic activity. 

satellite venera crosses planet venus

 Much of Venus's surface appears to be formed through volcanic activity. The number of volcanoes on Venus is more than Earth, with 167 large volcanoes that can reach up to 100 km wide. The only volcanic compound on Earth of this size is the Great Island of Hawaii. However, it does not mean that Venus is volcanically more active than Earth; it is due to the older Venus crust. By comparison, the surface of Venus is estimated to be 300-600 million years old, while on Earth, oceanic crust is continuously recycled through a subduction process at the boundary between tectonic plates, resulting in an average age of about 100 million years. ] Some evidence suggests the ongoing volcanic activity on Venus. During the Venera program launched by the Soviet Union, Venera 11 and Venera 12 rides found lightning, and Venera 12 recorded the thunder while landing. Venus Express launched by the European Space Agency also found lightning in the atmosphere. Although lightning on Earth is caused by rain, there is no rain on the planet Venus (although sulfuric acid drops from the atmosphere, and then evaporates at an altitude of 25 km above the surface). The possibility of lightning produced by ash from volcanic eruptions. Other evidence comes from measuring the levels of sulfur dioxide in the atmosphere, which is tenfold between 1978 and 1986. This suggests that initial sulfur dioxide levels are driven by large volcanic eruptions. Almost a thousand impact craters are spread evenly on the surface of Venus. In other cranial celestial bodies, such as Earth and the Moon, the craters appear to be degraded. On the Moon, degradation is caused by subsequent collisions, while on Earth the process is driven by wind and rain erosion. On Venus, 85% of craters are still in a state that has not been degraded. The number of craters and their un-degraded state indicates that the planet experienced a globally resurfacing event some 300-600 million years ago, which was then followed by reduced volcanism. While the Earth's crust is continuously moving, Venus's crust is suspected of not being able to support the process. Without the existence of tectonic tectonics that can reduce the temperature of the mantle, Venus undergoes a cyclical process that causes a rise in mantle temperature to ultimately weaken the crust. Then, for about 100 million years, large-scale subduction recycled the Venusian crust.

The diameters of the craters on Venus vary from 3 km to 280 km. There is no crater whose diameter is less than 3 km due to the influence of the dense atmosphere on the foreign object entering Venus. An object with a kinetic energy smaller than a certain number will be slowed down by the atmosphere so as not to produce a collision crater. An object with a diameter smaller than 50 meters will break and burn in the atmosphere before it reaches the surface.

Venus has a very dense atmosphere, which consists of 96.5% carbon dioxide and 3.5% nitrogen. Its atmospheric mass is 93 times larger than Earth's atmosphere, while the pressure on the surface of the Venus planet is 92 times larger than on Earth's surface-the pressure is roughly equivalent to the ocean as deep as 1 kilometer on Earth. Venus density on the surface of Venus was recorded at 65 kg / m³ or 6.5% of the water density. The atmosphere is rich in CO2 and the thick sulfur dioxide cloud produces the strongest greenhouse effect in the Solar System, so that the average surface temperature of Venus is 462 ° C (864 ° F). [11] [40] As a result, the surface of Venus is hotter than Mercury, which has a minimum surface temperature of -220 ° C (-364.0 ° F) and a maximum surface temperature of 420 ° C (788 ° F), though Venus is located farther from the Sun and as a result only acquire 25% of irradiance received by Mercury. The surface of Venus is often described as hell. The temperature at Venus is also higher than the temperature for sterilization.Research shows that billions of years ago, the atmosphere of Venus is more similar to the Earth's atmosphere than the present Venus atmosphere, and there may be water on the surface. However, after a period of 600 million to several billion years, a sustainable greenhouse effect is caused by the evaporation of water that produces greenhouse gases in the atmosphere. Although the surface of Venus can not support life as on Earth, the possibility of existence of a habitable niche in the lower and middle bottom layers can not be ignored.Thermal inertia and heat transfer by the wind in the lower atmosphere indicate that the surface temperature of Venus is not much different between the light and dark side, although the planet's rotation is very slow. The wind on the surface is slow with speeds of several kilometers per hour. However, due to the high atmospheric density on Venus's surface, the wind is significant and capable of removing dust and small rocks on the surface. In addition, the wind can also complicate pedestrians even when heat, pressure, and lack of oxygen are not a problem.

Above the CO2 layer there is a thick cloud composed of sulfur dioxide and sulfuric acid. The beginning reflects and scatters about 90% of sunlight, thus inhibiting the observation of Venus's surface. Due to this permanent starting layer, although the distance of Venus closer to the Sun than the Earth, the surface of Venus is not as bright as Earth. Winds as fast as 300 km / h (190 mph) above the clouds around Venus every four to five Earth days. Venus wind speed is 60 times faster than the rotation of Venus, while the fastest wind speed on Earth is only 10-20% of Earth's rotational speed.The surface of Venus is isothermal; the planet has a constant temperature not only between day and night, but also between the equator and the poles. The slope of the venous axis of less than 3 ° also minimizes seasonal temperature variations. The only considerable temperature variation depends on the altitude. In 1995, the Magellan vehicle successfully captured the image of a highly reflective substance at the top of the highest mountain that closely resembles the snow on Earth. This substance is likely to form from the same process with snow, albeit at much higher temperatures. The snow is too volatile on the surface, so as to rise to a cooler height in the form of gas, and then undergo precipitation. The identity of this substance is still not known for certain, but there are various speculations such as tellurium and lead sulphide (galena).

The Venusian cloud is capable of producing lightning like a cloud on Earth. The existence of lightning has been a controversy since its first discovery by the Venera rides. In 2006-07, Venus Express managed to find electromagnetic wave electrons, which are signs of lightning. Its intermittent appearance shows patterns related to weather activity. In 2007, Venus Express found the atmospheric vortex at the south pole of Venus. In addition, in 2011, this vehicle also managed to find the ozone layer in the upper atmosphere of Venus