Speaking of Venus, everyone is very familiar with it, but when it comes to Venus, many friends may not know, if you talk about Chang Gung Star, many friends may not have heard of it. In fact, Daystar and Chang Gung Star are both Venus.
People living in the city rarely see the bright big star in the eastern sky before dawn, because it is easily blocked by high-rise buildings, or flooded by light pollution in the city, but at dawn in the countryside, many times you can see the bright starter star shining in the night sky before the sun rises, its name means "open dawn", which is the sign that the day is coming, and sometimes even when the sun will be out of the horizon can see it, showing how bright it is.
In the evening, we can often see a bright big star in the western sky, at this time its name is Chang Gung Star, that is, longevity meaning, it and Daystar are actually Venus, but the ancients did not know that they are a star, so they gave it two names, but usually when you can see the Daystar in the morning, you can't see The Long Gung Star in the evening, because Venus will only appear on one side of the sun, and it is impossible to run to the other side overnight.
Venus is the brightest object in the canopy besides the sun and moon, why is it so bright? Because it is the closest celestial body to our earth besides the moon, the closest time is only 38 million kilometers, but when it is the brightest, it is not the closest to the earth, because at this time the back of Venus is facing our earth, usually we can only see the light of the sun hitting its atmosphere, and it is only brightest when it is at a great distance from the perihelion and the aphelion.
Another reason why Venus is very bright is that it is large enough, its diameter is close to 95% of the Earth, the mass is 80% of the Earth, but its atmosphere is thicker than the Earth, there are more clouds above, it can also reflect sunlight, its surface air pressure is equivalent to 96 times the surface atmospheric pressure, which is better than the earth's other neighbor Mars, mars Diameter is only half of the Earth, the atmosphere is also very thin, the surface air pressure is only equivalent to 0.8% of the Earth, so its apparent area is smaller, So Venus looks much brighter than Mars.
The planets in the image above are equally proportional to Mercury, Venus, Earth, and Mars from left to right.