5 facts about planet Earth. Quick Reference
We all know the main features of the planet that has not yet been observed on other planets - namely, the oceans of liquid water on the surface and of course the existence of life. However, many will be interested to learn about the other unique features of our planet, which have made possible the existence and evolution of life on it.
giant-iron
Earth is not only the largest of the rocky planets of the solar system, but also the most massive (in the solar system are bigger does not always mean massive). The mass of the Earth is estimated at 5, 97h10 24 sup> kg, while the mass of its "sister" Venus is less than 1, 1x10 24 sup> kg. To increase the mass of Venus to the mass of the Earth, we would not even have enough of all the material Mercury, Mars and the Moon combined (5, 8610 24 sup> kg in total). Only adding to the planetary "salad" Ganymede, the largest and most massive companion planet in the solar system (Jupiter), we could "outweigh" the stone giant. And only ½%.
The largest "stone" planets and moons of the solar system i>
This difference in weight is achieved and the fact that the Earth is the same and the densest planet in the solar system (5, 51g / cm 3 sup>). The acceleration of gravity (g) at its equator is similar to that at the level of the imaginary surface of most of the giant planets (with the exception of Jupiter, where g is more in 2, 5 times).
By the way the principle of "bigger does not mean massive": Ganymede twice as massive as the Moon, and its diameter is 8% more than the planet Mercury (5300km against 4900km), but it is inferior to the latter, by weight more than doubled! blockquote > natural nuclear reactor
Almost all the fans of physics and related sciences (such as astrophysics), familiar with the sources of energy from stars like the sun, where the reaction of thermonuclear fusion of hydrogen and helium. Active processes of "production" and the transfer of energy taking place inside large planets, but by diametrically opposite processes.
During the formation of the planet most dense and heavy elements such as iron, nickel and radioactive isotopes lowered into the center of the planet, the most easy to stay closer to the surface. Therefore, a differentiation of the inner layers of the planet. Therefore, large celestial bodies are relatively scarcity of heavy elements at the surface (one of the main reasons for the interest of earthlings to Mars). As a result, in the center of the planet formed iron-nickel core red-hot decay of radioactive elements up to 5700 ° C.
bowels of the Earth: 1-2 Inner and outer core of (total mass 28, the mass of the Moon 5); 3 Mantle (52 mass of the Moon). Earth's lithosphere (4) together with the hydrosphere and atmosphere make up no more than 1/3000 the mass of the planet i>
All this heat is given through the liquid outer shell and goes into the mantle. Actually the movement of the molten metal in the outer core and generates Earth's magnetic field. Through convection processes in the mantle of the energy reaches the Earth's crust - continental drift that we know the result of the constant movement of tectonic plates that form the earth's crust.
Ie The Earth is not just a giant boulder are active only at the surface, and a huge nuclear reactor, with active systems, heat dissipation and powerful magnetic field generators.
Magnetic Shield
The above mentioned Earth's magnetic field is also not typical of the terrestrial planets. More precisely the magnetic field of a similar nature was found and Mercury, but the Earth's magnetosphere with characteristics more like a giant planet's magnetosphere. By its strength at the equator, it is second only to Jupiter (10 times), superior to Saturn and Uranus, and is comparable to the strength of the magnetic field of Neptune (0, 3 G at the equator). However, the size of the magnetosphere and the magnetic dipole moment is significantly inferior to all of them.
Scheme of the magnetic field of the Earth. The ionosphere occurs when the ionization of the upper atmosphere by solar radiation. It has almost all the planets with relatively thick atmosphere and may reject part of the charged particles arriving from the surface of the Sun i>
The magnetic field strength (Gauss) expresses the force with which this field acts on the charged particles. blockquote> In contrast to the magnetospheres of the giant planets, Earth's magnetic poles do not meet the geographic, the north magnetic pole of the planet is located in the southern hemisphere, and south, respectively, in the northern hemisphere. The reasons for the geographical location of the magnetic poles are in their regular inversions in geological time scales (associated with the chaotic processes in the liquid outer core of the planet). The magnetic poles, traveling to the Earth's surface in the variable close to the geographic poles of the planet. The whole process takes from 1000 to 10 000 years, during which the "polar" radiance at certain periods can be observed at any latitude planet up to the equator. During such reversal magnetic field of the planet temporarily weakens, which may lead to an increase in background radiation on the surface of the Earth. Currently, the magnetic poles "travel" on a planet with a more increasing speed - more than 50 km / year today.
reversal of the magnetic poles of the Earth over the last 5 million years. Black marked inversion like modern. White - periods of reversion (magnetic poles lie in the respective geographic) i>
Scientists do not have data on positive correlation weakening of the magnetic field at its inversion with mass extinctions. But in any case, such a weakening of the "magnetic shield" Earth will not find humanity by surprise:
«Last time inversion of the magnetic field has occurred about 780 thousand years ago. If homo sapiens appeared 240,000 years ago, which means that our species has never experienced a geomagnetic reversal. The majority of scientists agree that the process from start to finish takes a few thousand years - from 2-3 to 7-10 thousand years. At the same time, however, the most active stage can take place within a thousand-year time frame. On the other hand, some experts believe that some reversal in the history of the Earth and could last thousands of years. In any case, it's not the years and decades, » i>
© Most popular doomsday scenarios in December 2012. Blockquote>
Month stability
If the chaotic processes in the Earth's core can not guarantee a stable orientation of the dipole magnetic field of the Earth, the natural satellite of our planet has been 4, 5 billion years provides a stable orientation of its geographic poles relative to its orbital plane around the Sun at an angle of 23, 5 ° (changing within 3 ° with a period of 000 to 100 years). This stability is the planet's axis of rotation of capital to provide a relatively constant conditions for the evolution of life on our planet. For example, Venus or Mars doomed randomly change the angle of the axis of rotation to the plane of the treatment, under the influence of tidal forces of the major planets and the sun. However, the axis of rotation of the Earth is subject to the so-called precession .
The rotation of the celestial body characterized by its motion around its axis of rotation, while the treatment itself expresses the movement of celestial bodies in orbit around another celestial body. Thus, the Earth does not revolve around the sun, and applies for 365 diurnal rotation of the Earth. Blockquote> The existence of such an overweight "stabilizer" in the orbit of our giant-iron so much more unites it with gas and ice giants. The moon has a transverse diameter of 3476 km and is the fifth of the mass of the satellite in the solar system (after the largest satellites of Jupiter and Saturn). His matter is easy enough for a 5 planetoids mass of Pluto, and the remainder will be enough for two of the asteroid belt between the orbits of Mars and Jupiter!
The relative size of the Earth, Moon and Pluto i>
Earth-Moon system has the lowest ratio of the mass of the planet and its satellite in the solar system (previously owned by the Pluto-Charon system) superior to the earth in this regard the Moon "only" 81 times. For example, Saturn exceeds by weight Titanium is almost 3000 times!
Universe sized speck ...
Most of the Earth's mass, combined with a powerful magnetic field and the largest natural satellite made the main contribution to the diversity of our planet's climate. Many of us remember how in science fiction sagas of heroes travel to different worlds in which dominated a particular type of climate. This rocky planet Vulcan of Star Trek, hot Tatooine, frozen hut and forest moon of Endor in Star giant warriors. Of course this is only a simplification of the authors, and the population of the planet can be a great climatic diversity, as on Earth. On our stony-iron giant is a place for the entire universe of all possible landscapes - and boundless oceans, forests and impenetrable jungle and, of course, for the vast dazzling icy surface of the pole.
In this final (but not the last), the amazing and unique features of our planet, I would like to conclude this brief overview. However, it would be better to give the floor for a long time who left us, but left a solid intellectual heritage of Carl Sagan:
«Take a look again at this point. It's here. This is our house. This is us. All the people you love, everyone you know, all of whom you've ever heard, everything ever existed people have lived their lives on it. Many of our enjoyment and suffering, thousands of self-confident religions, ideologies, and economic doctrines, every hunter and collector, every hero and coward, every creator and destroyer of civilization, every king and peasant, every enamored couple, every mother and father, each capable child inventor and explorer, every teacher of ethics, each lying politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there - on a mote, suspended in a sunbeam.
Voyager 1, 1990, the distance - 6 billion km i>
Land - a very small stage in the vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that in glory and triumph, they could become the momentary masters of the sand grains. Think of the endless cruelties committed by the inhabitants of one corner of this point of barely distinguishable inhabitants of the other corner. About how often differences between them, how eager they are to kill one another, how hot their hatred.
Our posturing, our imagined importance, the illusion of our privileged status in the universe - they all succumb to this point of pale light. Our planet - a lonely speck in the darkness of the surrounding space. In this enormous emptiness no hint that someone will come to our aid in order to save us from our own ignorance.
Land - is the only known the world capable of sustaining life. We have nowhere else to go - at least in the near future. To visit - yes. Colonize - yet. Whether you like it or not - the earth is now our home.
They say, astronomy instills humility and strengthens character. Perhaps there is no better demonstration of silly human conceit than this detached picture of our tiny world. I think it underscores our responsibility, our duty to be kinder to each other, to keep and cherish the pale blue dot - our only home. »
- Pale blue dot blockquote>
My publications close to the subject:
Extreme sister Earth. Past and Future "Morning Star»
Earthrise on the moon ... a common thing
What killed the "terrible lizards"? On the generators of mass extinctions
Source: geektimes.ru/post/260768/
