People have joys and sorrows, and the moon is cloudy and sunny.

Raise a glass to invite Mingyue, and the shadow becomes a trio.

Life must be happy, don't make the gold bottle empty to the moon.

......

From ancient times to the present, human beings have had a special affection for the moon, and there are countless legends and poems related to the moon.

Among them, most of the Chinese people about the moon are beautiful, such as the Mid-Autumn Festival, which symbolizes reunion, and Chang'e, which symbolizes love, and so on.

The West is different, vampires, werewolves, etc., are darker and more evil.

However, in the eyes of most people in modern society.

In their eyes, the moon is just a satellite of the earth, and it can also be said to be the "sun" of the night.

In the eyes of astronomy enthusiasts, the moon is beautiful and mysterious.

Because it is close to the Earth and easy to observe, many astrophotography enthusiasts will use the moon as their first photographic target.

The same goes for Lin Nan.

So after the failure to shoot the moon just now, Lin Nan was ready to take out his mobile phone to check his knowledge about the moon to see if it was the problem with the moon that caused him to shoot badly.

It turned out that the signal on the mountain was so poor that the webpage could not be opened at all.

After thinking for a while, Lin Nan said to Lin Wolf: "Dad, I can't shoot today, so I can only wait for the next monthly vacation." But it's summer vacation soon, and there's a lot of time to spare. During this time, I will first consolidate my knowledge of astronomy. ”

Timberwolf was very happy to see that his son had decided to start with the basics.

Timber Wolf didn't know anything about astronomy, but he knew that no matter what he did, the foundation was the most important.

Every high-rise building starts on a solid foundation.

Then Lin Wolf and Ye Xinlan told Lin Nan to go to bed early and went back to their room.

As for Lin Nan, after his parents left, he immediately took out the astronomical telescope from the equatorial mount.

Observation of the starry sky begins.

Lin Nan knows very well that every astrophotography enthusiast starts by observing the starry sky and being familiar with the starry sky.

You have to understand it before you can shoot it.

Lin Nan also understood that he was indeed a little ambitious, and he wanted to shoot when he came up.

However, it is not too late to observe, and although the moon is large and round today, and the moonlight is very bright, the brightest star in the night sky like Sirius is still visible.

Lin Nan remembered that he had seen it in the documents in the starry sky group, and he remembered very well the current division of human beings into cosmic stars, and even the specific numbers in them.

According to statistics, the total number of stars visible to the human eye with normal vision on the entire Earth is just over 6,000 stars.

Humans divide the brightness of stars according to their grades, including 20 stars of first magnitude, 46 stars of second magnitude, 134 stars of third magnitude, 458 stars of fourth magnitude, 1476 stars of fifth magnitude, and 4840 stars of sixth magnitude.

The first magnitude star is the brightest star, and the sixth magnitude star is a faint star that the human eye with normal vision can just distinguish, and the difference in magnitude between the two is 5 notches, the apparent brightness difference between the two is 100 times, and the apparent brightness difference between stars adjacent to the magnitude is 2.51 times.

At any given moment, we see only a little more than 3,000 stars from the sky, and the other 3,000 are below the horizon, so we can't see them.

The seniors in the group also said that to understand the starry sky, we should first know more than 60 brighter first and second magnitude stars that are easier to recognize, and then consider knowing some third and fourth magnitude stars, and as for the faint fifth and sixth magnitude stars, we should not consider them for the time being.

In other words, star recognition should be easy first and then difficult, step by step, and add up to a lot.

In this way, you can slowly become familiar with the whole night sky, the whole universe that you can see.

The stars seen by the naked eye, according to the shape of their arrangement, are divided into several regions by scientists, and these regions are called constellations.

As early as around the first millennium BC, the ancient Babylonians created 30 constellations.

Later, some European astronomers successively supplemented and developed it.

In 1922, the International Joint Congress of Astronomical Astronomical sorted out the constellation names used in history and determined them as 88 constellations (including 29 in the north sky, 12 in the ecliptic, and 47 in the south sky).

Soon after, the 1875 equinox and the equator were used as benchmarks. Each constellation varies in size and shape, but the stars in a certain area belong to that constellation.

Each constellation can be identified by the special distribution of bright stars in it, for example, the seven bright stars shaped like spoons (the Big Dipper) are called Ursa Major.

Constellation names are generally based on the shape of the stars combined with people's imagination, and are named after mythological characters (such as Andromeda, Cassiopeia), instrument names (such as sextants, microscopes, etc.) or animal names (such as cetus, crows, etc.).

The most commonly used star naming method used by astronomers is a method proposed by the German astronomer Bayer in the early 17th century, that is, taking the constellation as the surname, according to the order of the stars from light to dark, with Greek lowercase letters α, β, γ, δ, ε, ζ, etc.

After the 24 letters are used up, the lowercase Latin letters a, b, c, d, etc., if they are not enough, the uppercase Latin letters A, B, C, D, etc., but the letters after R are specially used to name variable stars.

The ancestors of China noticed some bright or characteristic stars very early on, and gave them various names, such as Vega, Cowherd, Mars, Antares, Betelgeuse, and so on.

Because Vega and Cowherd are the brightest stars in Lyra and Aquila respectively, they are also called α α Lyra and Aquila.

Lin Nan relied on the powerful memory possessed by his young brain to memorize all these basic astronomical knowledge in his mind.

But he can only talk on paper, and now standing under the night sky, Lin Nan looked at the twinkling stars on the black curtain, his eyes were still black, and he couldn't tell which star was called what and which star belonged to which constellation.

Lin Nan could only recognize the spoon-like Big Dipper now.

But this is generally known to everyone.

So this night, Lin Nan has been observing the stars in the sky with an astronomical telescope, and trying to make them coincide with the memories in his mind.

However, Lin Nan gained very little, only found a few stars with extremely obvious characteristics, and most of them were unrecognizable.

So after late at night, Lin Nan went to sleep.

He knew that astronomy didn't happen overnight, and that playing basketball was the same thing.

No matter what you do, rushing to achieve results is often too fast.

As for Si Fangxiang and Si Dong's father and daughter on the side of the villa, they drove home after the full moon of filming.

Unlike Lin Nan, Sidong has been nurtured by her father since she was a child, and her current astronomical knowledge is quite rich.

Si Dong knows that the full moon is the worst time to photograph the moon, and it is also the worst time to photograph the starry sky.

It's just that the monthly vacation is only once a month, and this month happens to be in the middle of the month, so Sidong can only come to see the full moon with his father.

And Lin Nan, who has a very high learning efficiency, almost had a comprehensive understanding of the moon in a week after returning to school.

Only then did Lin Nan know that he was a fool to choose to shoot the moon when the moon was full in the middle of the month.

First of all, the moon has a lunar phase, which means that it changes continuously with the revolution of the moon.

The Moon's orbital period is 27.3 days, while the synodic month's change period is 29.5 days.

The change of the moon's cloudiness and sunshine can be summarized into 8 basic patterns: the new moon (new moon), the waxing crescent moon, the first quarter moon, the waxing gibbous moon, the full moon (hope), the waning gibbous moon, the last quarter moon, and the waning moon.

These phases of the moon, alternating in order, repeat each other, forming a complete synodic cycle.

By observing the moon, astronomy enthusiasts can see the terrain of craters, moon seas, moon streams, canyons, and mountains.

The crater is formed by a meteorite crater or volcano, in short, it is a convex depression in the middle of the surrounding area.

There are more than 33,000 craters with a diameter of more than 1 km, accounting for 7~10% of the moon's surface area.

According to the International Astronomical Union, craters on the moon are usually named after famous astronomers or other scientists, such as Copernicus crater, Archimedes crater, Newton crater, Kepler crater, etc.

Among them, several are named after ancient scientists in China: Zhang Heng Crater, Zu Chongzhi Crater, Guo Shoujing Crater and Shishen Crater.

And Wanhu Crater is the first crater named after the Chinese.

The Moon Sea is a huge impact plain in ancient times, which was later covered by lava and is low-lying. Some small plains, named swamps.

Moon Creek and Canyon are small surface rifts on the moon. These canyons are of great interest to enthusiasts because of their strange shapes and a great test of eyesight.

As for the mountain range, it refers to a mountain body that extends in a certain direction and consists of several mountains and valleys.

Similar to craters, most of the moon's mountains are named after the Earth's mountain ranges.

Among them, the more famous are the Apennine Mountains: located in the center of the lunar surface, it is the longest mountain range on the moon, 3~4 kilometers higher than the lunar sea, and 1000 kilometers winding.

Leibniz Mountains: Near the south pole of the moon, the highest peak is 9,000 meters, and even Mount Everest, the highest peak on Earth, is a cut shorter.

Alps: On the surface of the moon, although not as majestic as the Alps on Earth, its high mountains and deep valleys are indeed unique.

When he saw these mountain range materials at that time, Lin Nan couldn't help but think that if someone climbed a mountain on the moon in the future, it would definitely be easier than climbing Mount Everest.

Although they are tall, the gravitational pull on the moon is small, and you might jump to the top of the mountain in a few jumps, haha.

And Lin Nan also knows why he can only shoot an outline through the understanding of the moon phase.

Because the Moon and the Sun are exactly 180 degrees apart at the time of the Full Moon, the Sun sets in the west and rises in the east of the Moon and is visible all night.

Although you can see the full view of the moon on this night, the full moon sun shines directly on the moon, and the front of the moon is white.

In astrophotography terms, the three-dimensional sense is very lacking, and the eyes can be easily tired.

Except for admiring the dark moon sea and the radiant patterns of the bright Tycho crater and the Copernicus crater, there is basically nothing to savor it.

With Lin Nan's entry-level equipment, coupled with rough shooting techniques and unskilled use of equipment, he couldn't shoot anything.

Therefore, Lin Nan also learned carefully and specifically about the other seven moon phases.