> > > Why is the Earth tilted?
Tilt of the Earth's rotation axis: description of the relationship between the planet and the orbital plane solar system with photo. Influence on seasons, day and night cycles, climate and weather.
Have you ever thought about why the Earth has an axis tilt? Why isn't the planet simply set perpendicular to the orbital plane? Researchers have been racking their brains for a long time to find the answer. The main debate is that the tilt of the rotation axis is based on the formation history of the entire solar system. We still don't have a clear vision, but we have a rough model.
The birth of the sun formed new source gravity. Tidal forces caused instability and the nebula began to fall, creating a disk and then planets. They collided to merge into larger objects. Most likely, there was a collision between the Earth and another object, and we tilted.
However, this is not a punishment, but a benefit. This is the ideal axial rotation angle to allow seasons to emerge that are firmly anchored in each hemisphere. Thanks to this, we have a favorable climate and harmonious temperature distribution. If it were perpendicular, one side would be constantly fried, and the ice age would reign on the other.
> > > Tilt of the Earth
Earth's axis tilt: description of the earth's axis in relation to the ecliptic of the solar system with photos, change of seasons, north and south poles, characteristics of precession.
Previously, it was believed that our planet could be flat, zigzag or cubic in shape. But long-term studies show that we are one of the spheroids orbiting our star.
We know a lot about the orbital path, distance from the Sun, and axial tilt. Let's understand what the Earth's tilt looks like.
Earth's tilt and earth's axis
The vertical planetary axis of rotation is located at a certain angle. This results in the sun's rays being distributed unevenly throughout the year. The angle reaches 23.44°.
Effect of Earth's tilt
Seasonal differences
It is this tilt of the Earth's axis that we have to thank for the changing seasons. When the north pole is turned towards the star, summer begins on it, and winter begins on the south pole. After 6 months they change places.
In addition, the angle of the Earth's inclination affects the daily cycle. In summer, the sun rises higher and the days last longer. The most extreme situation occurs over the Arctic Circle, where there is no daylight for part of the year, as well as 6 months of darkness at the North Pole (polar night). At the South Pole the situation is the opposite, where a day can span 24 hours!
Seasons are determined by the solstices (December 21 and June 21) and equinoxes (March 20 and September 22).
Changes over time
The axial tilt remains stable for a long time. But there is such a thing as nutation - swaying with a frequency of 18.6 years. The axis goes through this process which causes it to deviate slightly.
Precession causes the dates of the seasons to change on a cyclic basis of 25,800 years. This not only causes a difference between the green manure and tropical years, but also reverses the seasons. That is, in the northern hemisphere, summer will begin in December and winter in June.
The change in the length of the day also depends on precession. This is the moment when the dates of perihelion and aphelion change. In general, you see that axial rotation and orbital path are related to many factors. Believe me, people were once shocked to learn that the Earth was capable of moving. Even Copernicus and Galileo believed that we live on a perfect sphere.
This led to a displacement of the Earth's rotation axis by almost 10 centimeters, reported the National Institute of Geophysics and Volcanology of Italy.
The Earth's own axis (figure axis) is the axis around which the Earth is balanced in mass. The displacement of the earth's axis leads to an imbalance of the earth's and sidereal years and is associated with changes in astronomical coordinates. This phenomenon, on the one hand, is caused strong earthquakes, on the other hand, can lead to a further increase in natural disasters.
On March 11, 2011, an earthquake of magnitude 8.9 occurred in Japan. Its epicenter was located 373 kilometers northeast of Tokyo, and the source lay at a depth of 24 kilometers.
NASA Jet Propulsion Laboratory (JPL) scientist Richard Gross believes the earthquake could have shifted the Earth's axis by about 15 centimeters toward 139 degrees east longitude. The length of the day should be shortened by 1.6 microseconds.
Experts from the National Institute of Geophysics and Volcanology of Italy reported that, according to their calculations, the axis shifted by almost 10 centimeters as a result of the earthquake.
According to Leonid Zotov, an employee of the gravimetry laboratory of the Sternberg State Astronomical Institute (SAI) of Moscow State University, theoretical axis shifts of 6-8 centimeters were predicted for many large earthquakes, but they were not confirmed by observations.
Zotov notes that the observations needed to verify calculations can be obtained using several systems, in particular a constellation of GPS satellites, which determines the coordinates of the Earth’s geographic poles four times a day. It is possible to obtain these coordinates in a higher resolution, but to do this you need to run a processing program. This, as Zotov puts it, is “a non-trivial thing.” There is also a system of Very Long Baseline Radio Telescopes (VLBI), which provides coordinates once a day.
Leonid Zotov notes that these changes have not yet been observed, but if such monitoring can be carried out, “this will be great progress.”
If you carefully consider all the objects of the solar system, then without a doubt we can say that the Earth is lucky. During the formation of the planets, it was she who was destined to end up in the right place, where all the factors for the development of life were most harmoniously combined. It’s a paradox, but even with the development of progress in the field of space exploration and information accessibility, not all people have an idea of the cosmic parameters of the Earth, but it is they who should be thanked not only to humans, but also to all of nature for the opportunities that it provides for the development of the life cycle. It's time to fill this gap.
Special thanks to the orbit, atmosphere and axial tilt
Earth is the third farthest from main star planet. The average distance to the Sun is about 149.5 million km, it has become optimal for it in terms of temperature ratio - not too hot during the day and summer time, and moderately cold at night and in winter.
The Earth's orbit deserves respect for its location, not only due to its climate, but also because being in this part of the solar system created opportunities for the formation of an atmosphere conducive to the emergence of life, the basis of which is nitrogen and oxygen.
You should also pay attention to the angle of inclination of the earth's axis to the orbital plane. It is 23 degrees, thanks to it there are no completely shaded areas on the planet; each of them alternately receives the required amount of light and heat as the seasons change.
The air on Earth is not only oxygen...
Since childhood, people have known about the importance of oxygen. However, they rarely remember other components.
First of all, these include nitrogen - this gas is even larger than the first in the atmosphere in volume and its main task is to neutralize the negative properties of oxygen. Sounds strange? In fact, there is nothing surprising, because if you remember chemistry, it is known that O2 gas has the ability to create oxidative reactions, in its pure form it can even burn the respiratory tract! Therefore, nitrogen is a safety cushion for our mucous membranes of the nose and lungs.
And of course, a little carbon dioxide is present, only a few hundredths of a percent. Why is it so small, if so many people on the planet exhale it every second? It's very simple: carbon dioxide is transferred from humans to plants, which, when exhaled, return oxygen to the atmosphere. What a cycle!
The angle of inclination of the earth's axis and its gifts
As noted above, it allows any point on the planet to be charged with solar energy. But this is not his only merit. The tilted axis allows us to observe phenomena such as seasons, which are a consequence of the fact that at each latitude the sun's rays are directed at different angles, changing them throughout the entire 365 days, resulting in warmer and colder temperatures. And at the poles you can witness that for more than 180 days the sun does not set from the sky, and for the other 180 days it does not rise, because it illuminates the opposite pole. Thus, over the entire orbital cycle, the two hemispheres alternately heat up and cool down. When it’s summer on one of them, it’s summer on the other at the same time winter cold; with autumn and spring everything is similar. The length of day and night changes in each season.
If the angle of inclination of the earth's axis were zero, then the picture would be more faded: day and night would consistently last 12 hours, and the time of year and temperature would be the same, depending on latitude. The equator would be an oasis of summer, autumn would not leave the middle latitudes, and at the poles there would be neither day nor night, but only eternal morning.
Special differences from neighboring terrestrial planets
1. Our planet is the largest in size among them. Venus, and especially Mars and Mercury, are significantly inferior in size to it.
2. Only on Earth is oxygen present in sufficient quantity and in the correct ratio, which is important for the existence of life.
3. Has the strongest magnetic field, which protects against radiation and the largest natural satellite- The moon.
4. The only one of the planets Earth group has a huge reserve of water.
5. The distance to the Sun - about one and a half hundred million kilometers - turned out to be lucky for her.
Conclusion
Earth can rightfully be called Paradise! Nowhere in the immediate space region are there such favorable conditions. And we need to thank the cosmos for this, which created a comfortable angle of inclination of the earth’s axis and favorable orbital parameters. No neighboring planet has a satellite like the Moon, water, oxygen and life, which is beautiful anyway. And all that is required of people is to love and take care of her. Our planet deserves it.
What causes Earth's climate to change?
Astronomer Milutin Milankovich (1879-1958) studied changes in the Earth's orbit around the Sun and the tilt of our planet's axis. He suggested that cyclical changes between them are the cause of long-term climate change.
Climate change is a complex process and is influenced by many factors. The main one is the relationship between the Earth and the Sun.
Milankovic studied three factors:
Change in the tilt of the earth's axis;
Deviations in the shape of the Earth's orbit around the Sun;
The precession of the change in the position of the axis tilt relative to the orbit..
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Deviation of the earth's axis. |
Changing the Earth's orbit. |
 Earth Earth without seasons, axis tilt 0°. |
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 End of June: summer in the Northern Hemisphere, winter in the Southern. |
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 Late December: summer in the Northern Hemisphere, winter in the Southern Hemisphere. |
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Earth's axis tilt
If there were no axis tilt, then we would not have seasons, and day and night would last the same throughout the year. The amount of solar energy reaching a certain point on Earth would be constant. Now the planet's axis is at an angle of 23.5°. In the summer (from June) in the Northern Hemisphere, it turns out that northern latitudes receive more light than southern latitudes. The days are getting longer and the position of the sun is getting higher. At the same time, it is winter in the Southern Hemisphere. The days are shorter and the sun is lower.
WITH After six months the Earth moves in its orbit to the opposite side of the Sun. The slope remains the same. It's summer in the Southern Hemisphere, the days are longer and there's more light. It's winter in the Northern Hemisphere.
Milanković suggested that the tilt of the earth's axis is not always 23.5°. Fluctuations occur from time to time. He calculated that the changes ranged from 22.1° to 24.5°, repeating over a period of 41,000 years. When the slope is less, the temperature in summer is lower than usual, and in winter it is higher. As the slope increases, more extreme climate conditions are observed.
How does all this affect the climate? Even as temperatures increase, winter is still cold enough for snow in areas far from the equator. If the summer is cold, then it is possible that snow in winter at high latitudes will also melt more slowly. Year after year it will be layered, forming a glacier.
Compared to water and land, snow reflects more solar energy into space, causing additional cooling. From this point of view, there is a mechanism of positive feedback. As temperatures drop, more snow accumulates and glaciers increase. Reflection increases over time and temperature decreases, and so on. Perhaps this is how the ice ages began.
Shape of the Earth's orbit around the Sun
The second factor Milankovitch studies is the shape of the Earth's orbit around the Sun. The orbit is not perfectly round. At certain times of the year, the Earth is closer to the Sun than usual. The Earth receives significantly more energy from the Sun when it is as close as possible to the star (at the perihelion point), in comparison with its maximum distance (the aphelion point).
The shape of the Earth's orbit changes cyclically with periods of 90,000 and 100,000 years. Sometimes the shape becomes more elongated (elliptical) than it is now, so the difference in the amount of solar energy received at perihelion and aphelion will be greater.
Perihelion is currently observed in January, aphelion in July. This change makes the climate of the Northern Hemisphere milder, bringing additional warmth in winter. In the Southern Hemisphere, the climate is more severe than it would be if the Earth's orbit around the Sun were circular.
Precession
There is another difficulty. The orientation of the earth's axis changes over time. Like a top, the axis moves in a circle. This movement is called precessional. The cycle of such movement is 22,000 years. This causes the seasons to gradually change. Eleven thousand years ago, the Northern Hemisphere was tilted closer to the sun in December than in June. Winter and summer changed places. 11,000 years later, everything has changed again.
All three factors: axial tilt, orbital shape and precession change the planet's climate. Since this happens in various scales time, the interaction of these factors is complex. Sometimes they enhance each other's effect, sometimes they weaken each other. For example, 11,000 years ago, precession caused the onset of summer in the Northern Hemisphere in December, the effect of increasing solar radiation at perihelion in January and decreasing at aphelion in July would increase the interseasonal difference in the Northern Hemisphere, instead of the softening we are now accustomed to. Not everything is as simple as it seems, since the dates of perihelion and aphelion also shift.
Other factors influencing climate
Besides the effect of shifting the Earth's motion, are there other factors influencing climate?
