In the night sky, the five planets of Venus, Jupiter, Mercury, Mars, Saturn can be directly observed by us, and their brightness is very high, of which Venus is considered to be the brightest star in the night sky besides the moon, Jupiter is the second brightest star, Mars majority is comparable to Jupiter, Saturn and Mercury are also very bright. However, we can often see Venus, Jupiter, Mars and Saturn in the night sky, but Mercury is very rare, not only ordinary people, but also many people who like to look at stars have not seen it, including even the founder of heliocentric theory, the great astronomer Copernicus, who is said to have never seen Mercury in his lifetime.
What's going on? Mercury is also one of the five planets, so why is it so difficult to observe? Is the brightness not high enough? Of course not, as mentioned earlier, mercury's brightness is not low, and its brightest apparent magnitude can reach -1.9, which is brighter than the apparent magnitude of the brightest star Sirius, so why is mercury so bright not easy to see? To put it bluntly, there is no other reason than that it is too close to the sun.
Mercury is also bright compared to other stars in the night sky, but if it is compared to the Sun, it is too far away, and if it appears at the same time as the Sun, it will be completely submerged in the sun's brilliance. However, Mercury's orbit is too close to the Sun, hovering between 46 and 70 million kilometers, with an average distance of only 57.9 million kilometers, and when we look at Mercury, its angle to the Sun does not exceed 19 degrees. So when Mercury appears, either the sun is about to appear, or it is appearing at the same time, or the sun has already appeared, so with the strong sunlight, of course, it is difficult to see the traces of Mercury.
But you may be luckier than Copernicus, because just these few days (around January 25) are the time when Mercury is at its farthest east and when Mercury is at its furthest distance from the Sun, so every day after the sun sets below the horizon at dusk, we will be able to see the sparkling Mercury in the darkening night sky to the west, which is a rare window to observe Mercury.
However, the time to observe Mercury is very short, because it is very close to the sun, the sun will not fall soon, it will also fall below the horizon, so when the sun falls below the horizon to mercury falls below the horizon, the longest period of time will not exceed 111 minutes, so every time we can see Mercury with the naked eye, it will not exceed two hours, considering the change of light and other conditions, generally only in an hour or so, it is no wonder that the astronomer Copernicus has never seen Mercury in his life.
If it's at the west of Mercury, we'll be able to see Mercury in the morning, but that also means the sun is about to come out, so it's also a short time to see Mercury.
So would you like to take a look at Mercury? The opportunity to surpass Copernicus is coming, and at dusk on January 24 and 30, as long as the weather is clear, you are likely to be the luckier person than Copernicus.
Resources:
"China News Network" January 24 article "Two major celestial phenomena on the 24th "taking over the baton" staged"