The period of the Earth's rotation around its axis is a constant value. Astronomically, it is equal to 23 hours 56 minutes and 4 seconds. However, scientists did not take into account an insignificant error, rounding these figures up to 24 hours, or one Earth day. One such revolution is called diurnal rotation and occurs from west to east. For a person from Earth, it looks like morning, day and evening, replacing each other. In other words, the rising of the sun, noon, and the setting of the sun fully coincide with the daily rotation of the planet.
What is the axis of the earth?
The Earth’s axis can be imagined in the form of an imaginary line around which the third planet from the Sun rotates. This axis crosses the Earth's surface at two constant points - at the North and South geographical poles. If, for example, mentally continue the direction of the earth's axis upward, then it will pass next to the North Star. By the way, this is precisely what explains the immobility of the North Star. The effect is created that the celestial sphere moves around the axis, and therefore around this star.
It also seems to a person from Earth that the starry sky rotates from east to west. But this is not so. Visible movement is only a reflection of the true daily rotation. It is important to know that our planet is simultaneously participating not in one, but in at least two processes. It revolves around the earth's axis and performs an orbital motion around a celestial body.
The apparent movement of the Sun is the same reflection of the true motion of our planet in its orbit around it. As a result, first comes the day, and then the night. Note that one movement is unthinkable without another! These are the laws of the universe. Moreover, if the period of the Earth’s rotation around its axis is equal to one Earth day, then the time of its movement around the celestial body is a variable value. We find out what affects these indicators.
What affects the speed of the Earth’s orbital rotation?
The period of the Earth's revolution around its axis is a constant value, which can not be said about the speed with which the blue planet moves in orbit around the star. For a long time, astronomers thought that this speed was constant. It turned out that no! Currently, thanks to the most accurate measuring instruments, scientists have found a slight deviation in the previously obtained numbers.
The reason for this variability is the friction that occurs during high tides. It directly affects the decrease in the orbital velocity of the third planet from the Sun. In turn, the ebbs and flows are a consequence of the action on Earth of its constant satellite - the Moon. A man does not notice such a revolution of the planet around the celestial body, as does the period of the Earth's rotation around its axis. But we cannot help but pay attention to the changing seasons: spring gives way to summer, summer to fall, and autumn to winter. And this happens all the time. This is the result of the orbital motion of the planet, lasting 365.25 days, or one earth year.
It is worth noting that the Earth moves unevenly relative to the Sun. For example, at some points it is closest to the celestial body, and at others it is most distant from it. And one more thing: the orbit around the Earth is not a circle, but an oval, or ellipse.
Why does a person not notice the daily rotation?
A person will never be able to notice the rotation of the planet, being on its surface. This is due to the difference in size between ours and the globe - it is too huge for us! The Earth’s period of revolution around its axis cannot be noticed, but it will be possible to feel: day will be replaced by night and vice versa. This has already been mentioned above. But what would happen if the blue planet could not rotate around an axis? And here's what: on one side of the Earth would be an eternal day, and on the other - an eternal night! Awful, right?
It's important to know!
So, the period of the Earth’s revolution around its axis is almost 24 hours, and the time of its “travel” around the Sun is about 365.25 days (one Earth year), since this value is variable. Let us draw your attention to the fact that, in addition to the two considered movements, the Earth participates in others. For example, it, along with the other planets, makes a movement relative to the Milky Way - our native Galaxy. In turn, the Milky Way makes some movement relative to other neighboring galaxies. And everything happens because in the Universe there was never and will never be anything unchanging and motionless! This must be remembered for a lifetime.