What is the only non artificial satellite?

One rotation of the Earth on its axis is called a "day" and lasts about 24 hours. So, how long should a "day" be on the moon?

The Moon is a satellite of the Earth. While it revolves around the earth, it is also constantly rotating from west to east. Therefore, there is also the phenomenon of the sun rising in the east and setting in the west on the moon. However, this is completely different from the sunrise and sunset on Earth.

On the lunar surface, the alternation of black liquor and day is very sudden. You can't see the "morning and dusk" that can be seen on Earth (the state of the sky is still bright before sunrise and after sunset, this state is called "morning and dusk"). That's because there's no atmosphere on the moon that scatters sunlight.

It takes a long time to watch the sun rise in the east and set in the west from the moon. On Earth, the sun rises in the east at 6 o'clock in the morning and rises to midheaven at 12 noon, which is only 6 hours; It only takes 6 hours to slowly move westward from midheaven until it falls below the horizon; After 12 hours of darkness, the next day rises in the east and begins a new day. But not on the moon.

On the Moon, it takes more than 160 hours for the Sun to rise to midheaven after the Sun rises above the "horizon" in the east. It takes more than 160 hours from the midheaven to the western horizon to set; After more than 320 hours of black liquor, it can be regarded as a "day and night". This means that a day and night on the Moon (what is customarily called a "day") is about 4 weeks on Earth. Exactly:

A day and night on Earth is 23 hours, 56 minutes and 4 seconds (shortened to "24 hours"), while a day and night on the Moon are as long as days (i.e., a month of the "lunar calendar").

So, what does the day and night look like on the moon? On the moon, there is no air, no form of water, and no wind, clouds, rain, thunder, lightning, and other weather changes. When the sun comes out, because there is no atmosphere to shield it, the sun seen during the day spews out a scorching flame that shines brightly, far brighter than the sun seen on earth.

With no air and clouds (not absorbed and reflected by them), the temperature on the lunar surface can reach 127, and even the stones on the lunar surface are roasted! Interestingly, even in the daytime, on the Moon, you can clearly see the stars in the dark sky and the Earth that is incomplete due to the change of "geographic"!

As soon as the sun sets the "horizon", night immediately envelops the moon - the long "lunar night" begins. On the Moon, the night lasts for about 2 weeks. Moreover, due to the lack of protection from the atmosphere and clouds (there are no clouds, so there is no inverse radiation), the temperature of the lunar surface can drop all the way to -183.

In the dark night sky, you can see a huge "bright moon" - the earth that reflects the sunlight hangs high in the night sky, emitting a dazzling light, and the brightness is 80 times greater than the brightness of the moon we see on the earth!

Where the moth flies up

Sputniks are our "artificially made satellites". Scientists use rockets to launch it into a predetermined orbit that orbits the Earth or other planets for exploration or scientific research. The artificial satellite that orbits around which planet is called the artificial satellite of which planet, such as the artificial earth satellite that is most commonly used for observation and communication.

The Earth has a gravitational pull on the surrounding objects, so the thrown objects fall back to the ground. However, the greater the initial velocity of the throw, the farther the object will fly. When Newton thought about the law of gravitation, he imagined that when an object is thrown from a high mountain with different horizontal speeds, the speed will increase each time, and the landing point will be farther and farther away from the foot of the mountain.

If there is no air resistance, when the velocity is large enough, the object will never fall to the ground, and it will rotate around the earth to become an artificial earth satellite that moves around the earth, referred to as an artificial satellite.

A satellite refers to all celestial bodies in the universe orbiting around a planet, and which planet orbits is called a satellite of that planet. For example, the moon is the satellite of the earth, and the artificial satellite is the spacecraft that we humans have artificially created.

Meteorology, geological exploration, military, communications, navigation, etc.

There are communication satellites, meteorological satellites, reconnaissance satellites, navigation satellites, geodesic satellites, military satellites, ......

There are the Construction Number, the Corruption Number, the Time Number, the Recovery Number, and the Dispatch Number.

Artificial satellites include: communication satellites, meteorological satellites, reconnaissance satellites, navigation satellites, geodesic satellites, earth resources satellites, interception satellites, etc.

An artificial earth satellite is an unmanned spacecraft that orbits the earth and orbits more than one circle. Abbreviated as Sputnik. Artificial satellites are the most launched, most versatile, and fastest-growing spacecraft.

China's first artificial satellite, Dongfanghong-1.

Meteorological satellites use a wings to measure the earth's natural disasters in space, and then transmit them to the information station on the ground, and finally the information station is sent to everyone's mobile phone. ^_

Artificial satellites are used for a wide range of purposes, such as surveying terrain, surveying ground resources, and exploring underground mineral deposits; Meteorological satellites can take cloud images and observe wind direction and speed; spy satellites can collect military intelligence; Experimental satellites can help scientists do many experiments in space that cannot be done on the ground; Rescue satellites can search for distress signals from victims, etc.

There are many artificial satellites in the sky, such as communication satellites, meteorological satellites, reconnaissance satellites, navigation satellites, geodesic satellites, earth resources satellites, interception satellites, and so on.

There are peer satellites, rose punishments, and dangerous detective styles.

There are communication satellites, meteorological satellites.

Artificial satellite: An unmanned spacecraft orbiting the Earth in space orbit. Artificial satellites basically orbit the earth according to the laws of celestial mechanics, but the actual motion is very complicated due to the influence of the non-spherical earth's gravitational field, atmospheric drag, solar gravity, moon gravity and light pressure in different orbits.

Artificial satellites are the most launched, most versatile, and fastest-growing spacecraft. The number of satellites launched accounts for more than 90 per cent of the total number of spacecraft launched.

Artificial satellites can be divided into three main categories: scientific satellites, technical test satellites and application satellites. Scientific satellites are satellites used for scientific exploration and research, mainly including space physical exploration satellites and astronomical satellites, which are used to study the atmosphere, radiation belts, magnetosphere, cosmic rays, solar radiation, etc. of a certain planet, and can observe other stars.

A satellite is a natural celestial body that orbits a planet and orbits periodically in a closed orbit, and an artificial satellite can also be called a satellite. An artificial satellite is a device built by human beings and launched into space with space flight vehicles such as rockets and space shuttles to orbit the earth or other planets like natural satellites.