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 now it is the only inhabited planet known to mankind.
Interesting fact: planet Earth belongs to the group of planets of the earth group, which also includes Mercury, Venus and Mars.
The first attempts to measure the parameters of the Earth
The question of the size of the home planet worried the great sages in ancient times. One of these geniuses was the ancient Greek famous scientist and traveler Eratosthenes (who lived in the II century BC).
Once the sage 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 on this basis, Eratosthenes, using not complicated 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 6,290 km. This was a powerful impetus for measuring 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 globe at all. It is only a spheroid similar in shape. And therefore, not all the radii of the Earth are equal to each other.
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 XVII century, a method of measurement such as triangulation (or measurement by touching triangles) was mastered in order to find out how much is the globe. This measurement was carried out only during long expeditions and travels. The convenience of the method was that very often obstacles encountered on the way (such as forests, swamps, rivers, quicksands, and much more) could not interfere with the exact 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 elevations), angles were determined (using a telescope) with opposite points (C and D), knowing the length of the sides AB, BC and degrees of angles, it was possible to determine the size of the triangle ABC. And knowing the sides of CB, BD and degrees of angles - calculate the size of the triangle BCD. A negative feature of this method is that it is quite difficult, painstaking work and not everyone succeeded in doing it successfully.
Why could scientists not 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 divide the seas, straits and oceans. And in the open sea it is impossible to implement a method of measuring distance by triangles. The relief of the earth's surface also played a role. Mountains, ranges and other features of the landscape significantly impeded and distorted the resulting numbers from their true size. That is why for a long time the measurements of the area of the globe were very relative.
Grand 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 measuring instruments and launching a satellite into orbit of the planet, not only study of the shape of the Earth and nearby cosmic bodies became available, but also the opportunity to find out the area of the total surface of the earth. The use of satellites 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 of measuring parameters
In the era of the prosperity of technological progress and the human mind, scientists use three main approaches to measuring Earth’s distances:
- Radio wave measurement. 70 different telescopes (radio telescopes) are located 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 the calculations.
- Satellite ranging (or laser research). It seems to some that the satellites plowing the cosmic expanses within the Earth’s orbit do not perform any important functions. It's not like that at all! Scientists have long been using laser ranging 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 many classic paper maps. But this technology is primarily needed so that scientists around the world can measure the parameters of their home planet with maximum accuracy.
Shape definition
Space exploration by humans has made it possible to prove that the scientist Newton (who claimed that the Earth has the form of a “mandarin”) was right about the model of an inhabited planet. It is really “flattened” at the poles due to the action of centrifugal force. From this it follows that the radii of the planet are different.
Difficulties in measuring the area of the planet
Even with the measurement of relatively small distances and areas, many difficulties of various kinds can arise, let alone the measurement of such a large object as a whole planet. The most frequent obstacles in measurements carried out in ancient times were such interference as mountains, adverse weather conditions (rains, fogs, blizzards, snowstorms, 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 reason for the inaccuracy of the measurements. But there was such a thing as a “measurement instrument error”. At a short distance, such an error is insignificant and almost invisible to the naked eye, but in the matter of determining the area of the globe, such an inaccuracy could distort the dimensions of the home planet too much.
Attention! Different sources give different information about what sizes and what area of the globe. It is very important to be careful and double-check the data in order to avoid errors.
Scientists and modern data analysis
Research on the planet does not stop even for a minute. Every year new discoveries are made, which, no doubt, affect the further development of the human and animal world. But despite new advances, researchers are checking the data that have been obtained for a long time. Such a recheck can help scientists better understand the nature of changes on the planet and build a chain of events that can cause the transformation of various systems and properties of the planet.
For example, melting 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 a state.
Planet in numbers
What in general can be said about our planet?
- 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 square meters. km
- The area of the planet occupied by water is 361 132 000 square meters. km
- The average temperature is 14 o C.
Interesting facts about the planet
Interesting information:
- Planet Earth is a satellite of the Sun.
- Most of the planet has not been explored.
- Earth is the densest planet of all in the solar system.
- Over 60% of fresh water is frozen (in the form of glaciers and “polar caps”).
- All the continents that can easily be found on geographical maps, once upon a time were one.
- The marine topography is more pronounced than the surface topography.
- Formed a planet from the nebula.
- In orbit of the planet there are more than 15,000 active artificial satellites.
Danger to the planet
The main threat to the Earth and its inhabitants (today) is the fall on the surface of the planet of large cosmic bodies (asteroids). They can not only destroy many living organisms, but also seriously change the relief of the planet. And some are able to move the Earth off the 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.
An interesting hypothesis: some scientists suggest that the Moon (a natural satellite of the Earth) was once part of the planet.
"Bright" future of the planet
The existence of all the planets of the solar system is completely dependent on the "vital activity" of the sun. Scientists suggest that constant changes in a nearby star will lead to higher temperatures, evaporation of fresh and salt waters, and many other cardinal changes. The most terrible assumption of scientists is that the Sun, increasing in mass and volume, will be able to absorb the Earth. But this will not happen at all 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 in 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 devoted to research and measuring the area of the planet. No fewer scholars who have suggested the origin of life and the shape of the earth have been persecuted by religious leaders and their contemporaries.
But, fortunately, the “dark” times are gone. Mankind, having at its disposal a great many modern achievements of the technical process, can obtain reliable information about the planet on which it lives.