Earth, like any other celestial object, is in constant motion. We don’t feel it because it’s like an airplane or a car - we move at the same speed as transport, because of this the illusion of static is born.
What causes the Earth to rotate around its axis?
The graceful 24-hour rotation of the Earth around its axis is one of the reasons why our home planet is inhabited. In many ways, this is what allowed life to develop, thanks to the creation of a favorable temperature, which is achieved by a constant change of day and night.
Do not forget that not only the Earth has such a feature - each planet in the solar system has its own unique rotation. For example, on tiny Mercury, which is closest to the Sun, one rotation occurs in 59 Earth days, and on Venus - generally 243, and in addition, its movement occurs in the opposite direction.
Everyone knows that the Earth is spinning, and this seems trivial information, but if you think about it, it’s not entirely clear why this is happening. To answer this question, you need to find out how the entire solar system was formed.
Initially, the solar system was just a huge cloud of dust and gas, which eventually began to collapse, turning into a giant disk. He, in turn, constantly increased his speed of rotation, like a figure skater throwing her arms up to move faster. The sun formed in the center, and the planets began to gather away from it. All the objects that make up our system are on the same plane and move in the same direction because they all came from the same disk of cosmic dust.
While the process of gluing together the planets and other celestial bodies took place, there was no peace in the solar system, since the debris constantly collided with each other, which led to their rotation. Sometimes the gravity of large debris enticed small ones - this is how satellites appeared.
Why does the Earth rotate around its axis faster than other planets?
Scientists suggest that a huge object, about the size of Mars, crashed into our planet and separated from it a huge piece, which later became the Moon. This collision caused the Earth to rotate at a faster speed than other planets.. But the gravity of the moon affects the rotation of the earth - it slows it down!
Interesting fact: Earth is constantly slowing down. Scientists suggest that at the time of the formation of the planet, the day was only 6 hours. And now there are extremely accurate technologies that make it possible to calculate a further slowdown - in a hundred years the day will be shorter by 2 milliseconds.
At what speed does the earth rotate around its axis?
Speed is a relative concept, because it always takes a certain reference point to calculate it. To calculate the speed of rotation around its axis, the rotation relative to the center of the planet is taken.
The Earth makes one revolution in 23 hours 56 minutes and 4.09053 seconds, which is called the stellar period. The circumference of the planet is 40,075 kilometers. In order to calculate the speed, you need to divide the circle by time, then it turns out about 1674 km / h or 465 m / s.
The earth rotates around its axis at a speed of 1674 km per hour or 465 m / s.
The dependence of the Earth's rotation speed and latitude
But do not forget that the circumference of the planet varies depending on latitude, as the Earth narrows closer to the poles. Therefore, the planet is spinning at different speeds at different latitudes! The smaller the radius, the lower the speed. So at the North Pole and South Pole the rotation speed is practically zero.
If you are interested in knowing the rotation speed that can be achieved at a different latitude, then you only need to multiply the cosine of this latitude (you can calculate it on a calculator or just look in the cosine table) by the planet's rotation speed at the equator (1674 km / h). So the cosine of 45 degrees is 0.7071 and it turns out that the speed at this latitude is 1674x0.7071 = 1183.7 km / h.
Earth rotation speed for different latitudes
- 10 °: 0.9848 × 1674 = 1648.6 km / h;
- 20 °: 0.9397 × 1674 = 1573.1 km / h;
- 30 °: 0.866 × 1674 = 1449.7 km / h;
- 40 °: 0.766 × 1674 = 1282.3 km / h;
- 50 °: 0.6428 × 1674 = 1076.0 km / h;
- 60 °: 0.5 × 1674 = 837.0 km / h;
- 70 °: 0.342 × 1674 = 572.5 km / h;
- 80 °: 0.1736 × 1674 = 290.6 km / h
Interesting fact: space agencies prefer to use the Earth's rotation around its axis for its advantage. Since the rotation speed is greatest in the equator region, less resources are required for raising a spaceship from zero latitude.
Cyclic braking
Scientists began to notice a correlation between seismic activity over the year and the speed of the Earth's rotation around its axis. It is believed that there is no direct relationship between these two phenomena, but it is important for specialists to find any clues that, firstly, will give a greater understanding of our planet, and secondly, can save thousands of lives.
Since everything is cyclical, so the rotation of our home planet is cyclical. The earth has five-year periods of cyclic braking and acceleration.
Earth axis wobble
In physics, there are two concepts that are used to describe the oscillations of the Earth's axis - precession and nutation.
Precession is a phenomenon in which the angular momentum of a celestial body changes its orientation in space. Such a movement can be seen in the example of a top, which at startup has a vertical axis of rotation, but the top has the property of gradual deceleration, during which the speed begins to be lost. Because of this, the axis begins to gradually deviate from the usual vertical. Due to this, the top begins to describe a shape similar to a cone .. Such a movement is a precession.
With the Earth, things are more serious and slower. An antique geographer and astronomer Hipparchus also noted such a feature in the movement of our native planet, calling this phenomenon the eve of the equinox. The Earth’s procession cycle is extremely long - 25 thousand years. It is with this movement of the planet that scientists associate periodic changes in the climate. So at some point, the fluctuations will become so noticeable that it will be impossible to navigate through the old celestial maps due to the displacement of all stars relative to the equatorial line.
Nutation is a rather weak movement that resembles a kind of rocking or nodding characteristic of a solid body performing a procession. These are small oscillations of the earth's axis superimposed on the precession movement.
The motion of the earth around the sun
Do not forget that the motion of the Earth consists not only of its own rotation, but also of motion around the sun. Our house is located approximately 149.6 million kilometers from the star.
Our planet travels all the way around the star in 365,256 days at a speed equal to 108,000 km / h or 30 km / s.
Interesting fact: People recognized that the Earth revolves around the Sun, and not vice versa, only in the 16th century! For such "blasphemy" some scientists even paid with their lives.
Other movements
The solar system is not some kind of static object that does not move. In fact, simultaneously with all the rotations that occur in the system, it itself moves with great speed.
The sun is approximately 26,000 light years from the center of the Milky Way galaxy, which is approximately 80,000 to 120,000 light years wide. And its thickness is 7,000 light years. Our system is located on one of the far arms closer to the edge. It takes her about 200-250 million years to complete one revolution around the center of our galaxy.. In this orbit The solar system moves at a speed of about 250 km / s.
The Milky Way, in turn, also applies to an even larger system - the Local Group. Scientists gave this name to the gravitationally bound group of galaxies, to which our native belongs. In this system The Milky Way moves at a speed of approximately 300 km / s.
What will happen if the Earth suddenly stops abruptly?
The probability that you can just fly out into outer space at any time is zero. This helps you gravity, which relentlessly draws us to the ground. But Earth's gravity is not the same everywhere! Our planet has a spherical shape and due to rotation around its axis, the Earth is slightly flattened at the poles. The speed on the widest circle should be the highest - such a circle is the equator. Equator gravity is 0.3% stronger!
NASA says stopping the planet is not possible in the next several billion years. But if we imagine such a situation that the Earth stops abruptly, the result is not a rainbow picture. If the rotation of the celestial body itself ceases, then no one will stop the movement of the atmosphere, so everything that was on the surface of the earth will be destroyed by a strong wind. And this applies not only to people and animals, but also to buildings, trees, and even the upper layers of the soil!
The option with a gradual slowdown is the real situation that our planet will face in the distant future. The smallest speed to which the Earth can descend is equal to one revolution in 365 days. This situation is called “synchronicity of the sun." Then one side will always be turned towards the Sun, the other - as with the Moon, will forever be in darkness. But a similar situation, in general, according to NASA, can be used to.
Let's go back to a complete halt: if the Earth stops completely, then most likely the magnetic field, which is created primarily due to the back of the planet, will disappear. Because of this, we would lose the Van Allen radiation belts and the northern lights, which would leave us completely defenseless against cosmic radiation. In this case, with every burst of radiation on the Sun, the Earth would receive such a dose of radiation that hardly any living thing would remain.
But do not worry! The probability of such scenarios is practically zero!
