Mass And Gravity:
Venus’ mass is about 3.3 x 10(23) Kg. The gravity on Venus I 91% of the gravity on Earth. A 100-pound person would weigh 91 pounds on Venus. The density of Venus is 5,240 kg/m, slightly less dense than the Earth and the third densest planet in our Solar System (after the Earth and Mercury).
Length Of A Day And Year on Venus:
Venus rotates very slowly. Each day on Venus takes 243 Earth days. A year on Venus takes 224.7 Earth days. It takes 224.7 Earth days for Venus to orbit the Sun once. The same side of Venus always faces Earth when the Earth and Venus are closest together.
Venus’s Orbit And Distance From The Sun:
Venus is 67,230,000 miles (108,200,000 km) from the Sun. Venus has an almost circular orbit. On average, Venus is 0.72 AU, 67230,000 miles = 108,200,000 km from the Sun. Venus rotates in the opposite direction of the Earth (and the other planets, except possibly Uranus). Looking from the North, Venus rotates clockwise, while the other planets rotate counter clockwise. From Venus, the Sun would seem to rise in the west and set in the east (the opposite of Earth). No one knows why Venus has this unusual rotation.
Temperature On Venus:
Venus is the hottest planet in our Solar System. Its cloud cover traps the heat of the sun (the greenhouse effect), giving Venus temperatures up to 480*C. The mean temperature on Venus is 726 K (452*C = 870*F).
Moons:
Venus has no moons.
Inside Venus:
Venus ha a rocky crust, a thick basaltic rock mantle and a nickel-iron core. There is no surface water. The surface of Venus has been mapped through its cloud layer using radar. The surface of Venus is covered with roughly 20 percent lowland plains of solidified lava, 70 percent rolling uplands and 10 percent highlands (volcanoes, craters, mountains). The two major plains are called Aphrodite Terra Highlands (about half the size of Africa) and Ishtar Terra (a lava filled basin which is bigger than the United States). At the surface, there are relatively slow winds. Venus does not have a very strong magnetic field; this may be because of the planet’s slow rotation or perhaps Venus’s core lacks a molten outer layer.
Venus’s Atmosphere And Cloud Cover:
A thick layer of clouds covers Venus. These clouds are made mostly of sulphuric acid and are very fast moving, going up to 220 miles per hour (350 km per hour). The clouds rotate 60 times faster than the planet rotates. The cloud circle Venus in four Earth days; the planet rotates around its axis in 143 Earth days. These quickly moving clouds distribute the heat around the planet, making the night side hot also. V-shaped cloud patterns are visible in the middle latitudes when the clouds are examined in ultraviolet light. The clouds rain sulphuric acid (extremely acid rain), but this corrosive precipitation does not reach the surface. The high heat beneath the clouds (up to 220*C) evaporates the raindrops about 10 miles (30km) above Venus.
Atmosphere:
Venus’s atmosphere is mostly gaseous carbon dioxide (96%). The remaining components are: 3% nitrogen and 0.003% water vapour. Venus may have had a lot of water sometime in the past, but it probably boiled away in Venus’s high temperatures.
The atmospheric pressure on Venus is enormous, about 90 times greased than the atmospheric pressure on the Earth’s surface. The greenhouse effect traps heat in the atmosphere. The thick carbon dioxide atmosphere let’s very little infrared radiation escapes into spaced; most is reflected back to the planet.
Venus Spacecraft Visits:
Venus has been visited by spacecraft over 20 times. NASA’s Mariner 2 in 1962, and others visited it.
