Besides the sun and the moon, Venus is the brightest object in the sky. When it appears in the east at sunrise, it is usually called the morning star, and when it appears in the west at sunset, it is usually called the evening star.
When viewed through a telescope, Venus looks like the moon. This is because Venus is closer to the sun than the Earth. Observers on the earth can see Venus from the side and back, or they can see it from the front-planets farther away from the sun than the earth can only see the scene that is almost completely illuminated and facing our earth. The phase of Venus is one of the evidences used by Galileo, an astronomer in the17th century, to prove that the earth itself moves around the sun. Venus's total view looks smaller and darker because it happens on the side of the earth far from the sun. The phase and position of Venus in the sky are repeated every 1.6 years.
Seen from the earth, when planets pass through the surface of the sun, transits are rare, appearing in pairs every more than a century. The last transit occurred in 2004. The second transit of this pair will be at 20 12.
The average distance of Venus orbiting the sun is about 108 km. Venus is the closest planet to the Earth, and the closest distance to the Earth is about 41100,000 kilometers (25.4 million miles).
Venus orbits the sun counterclockwise every 224.7 days, in the same direction as other planets in the solar system. Its axis is almost vertical and its orbit is almost circular, so Venus doesn't experience four seasons like Earth and Mars, because its axis is more inclined and its orbit is more elliptical. Venus rotates very slowly, once every 243 earth days. Venus' rotation is retrograde, which means that the planet turns from east to west when viewed from its north pole. The earth and most other planets turn from west to east.
Venus is only slightly smaller and less dense than the earth. The surface gravity of this planet is nine tenths of that of the earth; An object weighing 10 kg on earth will weigh 9 kg on Venus.
The extreme conditions on Venus make it impossible for humans to set foot on this planet-there are no plans for manned exploration at present. If humans reach Venus, they will be as heavy as people on earth, but they will find a completely strange world and need a lot of protection to avoid high temperature and high pressure. The suffocating atmosphere is so dense that even a slow breeze feels like a huge gust. Although the night will last for more than 58 days, it will not be dark-the whole rock landscape will glow dark red. Venus may be the closest thing in the solar system to the hell imagined by human beings.