Earth is a unique world in which an infinite number of living macro- and microorganisms coexist. Everyone knows that the only inhabited planet in the solar system does not belong to the group of giant cosmic bodies. But the area of the globe is impressive.
What makes it unique is the fact that it is now the only habitable planet known to mankind.
Interesting fact: the planet Earth belongs to the group of terrestrial planets, which also includes Mercury, Venus and Mars.
First attempts to measure the parameters of the Earth
The question of the size of the native planet worried the great sages in ancient times. One of these geniuses was the ancient Greek famous scientist and traveler Eratosthenes (who lived back in the 2nd century BC).
Once a wise man noticed that the position of the sun in the sky on the same day (on the day of the solstice) in two cities of Egypt (Alexandria and Siena) is different. And based on thisEratosthenes, by simple calculations and the use of a special device (skafis), determined that the circumference of the planet is approximately 40,000 km, and the radius is 6290 km. This was a powerful impetus to measure the surface area of the globe. The sage was very close to the correct value (the average radius of the planet is 6371 km).
Important: the globe is not a sphere at all. It is only close in shape to a spheroid. And therefore, not all radii of the Earth are equal.
Triangulation - as a way to calculate distances
Without modern computing devices and the achievements of the high-tech era, our ancestors could answer the question of what is the land area of the globe. But only experienced and very attentive observers could do this.
In the 17th century, such a measurement method as triangulation (or measurement by contiguous triangles) was mastered in order to find out how much the area of the globe is. This measurement was carried out only during long expeditions and travels. The convenience of the method was that the obstacles very often encountered on the way (such as forests, swamps, rivers, quicksand, and much more) could not interfere with the accurate determination of the distance, since the calculations were carried out on paper.
The measurements were carried out as follows: from two points A and B (as a rule, these were hills, fortresses, towers and other hills), the angles were determined (using a telescope) with opposite points (C and D), knowing side lengthAB, BC and degrees of angles, it was possible to determine the size of the triangle ABC. And knowing the sides CB, BD and degrees of angles - calculate the size of the triangle BCD. The negative feature of this method is that it is quite difficult, painstaking work and not everyone was able to successfully complete it.
Why couldn't scientists determine the exact area of the Earth?
The answer is quite simple! On planet Earth there are huge continents and islands of various sizes that separate the seas, straits and oceans. And in the open sea it is impossible to implement the method of measuring the distance with triangles. The relief of the earth's surface also played a role. Mountains, ridges and other features of the landscape greatly hampered and distorted the figures obtained from the true size. That is why for a long time the measurements of the area of the globe were very relative.
Great breakthrough
Triangulation has long been the main and most accurate method of measuring area and distance. But with the advent of a new era, the invention of many instruments for measurements and the launch of a satellite into the orbit of the planet, not only did it become available to study the shape of the Earth and nearby cosmic bodies, but it also became possible to find out the area of \u200b\u200bthe total surface of the earth. The use of satellites has also helped to determine that the Earth is more than 70% water, and land makes up only 29% of the total area. It was found that the area of the globe is 510,072,000 square meters. km.
Modern methods for measuring parameters
In an era of flourishing technological progress and human intelligence, scientists use three main approaches to measuring the distances of the Earth:
- Measurement of radio waves. There are 70 special telescopes (radio telescopes) in different parts of the planet. They pick up radio waves (or quasars) and transmit data on the length of these waves to one computer, which performs calculations.
- Satellite ranging (or laser research). It seems to some that the satellites that surf space within the Earth's orbit do not perform any important functions. It's not like that at all! Scientists have been using laser ranging for a long time to determine the size of huge objects (continents, islands, rivers, continents and the planet as a whole).
- Satellite systems. Satellite navigation programs have made a significant contribution to people's lives. GPS systems have replaced the classic paper maps in many ways. But this technology is primarily needed so that scientists around the world can measure the parameters of their native planet with maximum accuracy.
Shape definition
Human space exploration proved that the scientist Newton (who claimed that the Earth was shaped like a “tangerine”) was right about the model of a habitable planet. It is really "flattened" at the poles due to the effect of centrifugal force. From this it follows that the radii of the planet are different.
Difficulties in measuring the area of the planet
Even withBy measuring relatively small distances and areas, many difficulties of a different nature can arise, to say nothing of measuring such a large object as an entire planet. The most frequent obstacles in measurements taken in ancient times were such interference as mountains, adverse weather conditions (rain, fog, blizzards, snow storms, etc.) and, of course, the human factor.
With the invention of various measuring instruments and satellites, the difference in relief, huge bodies of water (oceans, seas) and the action of meteorological factors were no longer the main cause of inaccurate measurements. But such a thing as “measuring instrument error” arose. At a short distance, such an error is insignificant and practically invisible to the naked eye, but in determining the area of the globe, such an inaccuracy could distort the size of the home planet too much.
Attention! Different sources give different information about what size and what area of the globe. It is very important to be careful and double-check the data in order to avoid mistakes.
Scientists and modern data analysis
Research of the planet does not stop even for a minute. Every year new discoveries are made, which, no doubt, influence the further development of the human and animal world. But despite the new achievements, researchers are checking the data that were obtained a long time ago. Such a recheck can help scientists better understand the nature of the change on the planet and build a chain of events that can causetransformation of various systems and properties of the planet.
For example, the melting of ice caused by global warming can increase the volume of the world's oceans. Consequently, the land area will decrease significantly, and this may cause the extinction of some species. Continuous research is the way to solve many global problems. As well as the problems of this or that state.
Planet in numbers
What can we say about our planet in general?
- The total surface area of the globe is 510,072,000 square meters. km.
- The planet is over 4.5 billion years old.
- The mass of the Earth is 589,000,000,000,000,000,000 tons.
- The area of the globe without water is 148,940,000 sq. km.
- The area of the planet occupied by water is 361,132,000 sq. km.
- The average temperature is 14 oC.
Interesting facts about the planet
Interesting information:
- Planet Earth is a satellite of the Sun.
- Most of the planet is unexplored.
- Earth is the densest planet of all in the solar system.
- More than 60% of fresh water is frozen (in the form of glaciers and polar caps).
- All the continents that can be easily found on geographical maps, once upon a time were one.
- Sea relief is more pronounced than surface relief.
- A planet formed from a nebula.
- There are more than 15,000 active artificial satellites in orbit around the planet.
Dangers for the planet
The main threat to the Earth and its inhabitants (today) is the fall of large cosmic bodies (asteroids) onto the surface of the planet. They can not only destroy many living organisms, but also seriously change the relief of the planet. And some are capable of shifting the Earth off its axis, which can lead to irreparable changes in the entire solar system. Every year, many asteroids approach the planet, but only 20% of them can cause serious damage.
Interesting hypothesis: some scientists suggest that the Moon (Earth's natural satellite) was once part of the planet.
“Bright” future of the planet
The existence of all the planets of the solar system depends entirely on the "life activity" of the Sun. Scientists suggest that constant changes on a nearby star will lead to an increase in temperature, the evaporation of fresh and s alt water, and many other dramatic changes. The most terrible assumption of scientists is that the Sun, increasing in mass and volume, will be able to swallow the Earth. But this will not happen soon, and humanity has the opportunity to find ways of salvation.
The study of the earth's surface and the planet as a whole began from ancient times. Even before our era, the great sages and thinkers of that era were tormented by the question of the size, shape and properties of the Earth. Many travelers died during long wanderings and expeditions dedicated to research and measurement of the planet's area. No less number of scientists who suggested the origin of life and the form of the Earth were persecuted by religious leaders and their contemporaries.
But, fortunately, the “dark” times are over. Mankind, having at its disposal a huge number of modern achievements of the technical process, can obtain reliable information about the planet on which it lives.
