The universe is the whole infinite world around us. These are other planets and stars, our planet Earth, its plants and animals, all this is the Universe, including what is outside the Earth- space, planets, stars. This is matter without end and edge, taking on the most diverse forms of its existence. The universe is everything that exists. From the smallest dust particles and atoms to huge accumulations of matter star worlds And star systems. The universe, or cosmos, is made up of giant clusters of stars. These huge star systems are called galaxies.
According to modern concepts, the Universe we are currently observing arose 13.7 ± 0.2 billion years ago from some initial singular state with gigantic temperature and density, and since then it has been continuously expanding and cooling. IN Lately scientists were able to determine that the rate of expansion of the universe, starting from a certain point in the past, is constantly increasing, which refines some of the concepts of the Big Bang theory.
Big Bang(Eng. Big Bang) is a generally accepted cosmological model describing the early development of the Universe, namely, the beginning of the expansion of the Universe, before which the Universe was in a singular state. (The word singularity means that it is something incomprehensible to science.)
8. The appearance of elementary particles, gaseous inhomogeneities, first-generation stars…
The universe began with the Big Bang about 15 billion years ago. At that moment, it had a negligible size and an incomprehensibly high temperature. It quickly expanded and cooled down. Its initial composition - photons (radiation) and quarks - elementary particles, soon followed by heavy subatomic particles - protons and neutrons. As the universe continued to expand and cool, nuclei such as hydrogen and helium arose from protons and neutrons. Simultaneously with the continued expansion and cooling of the Universe, hydrogen and helium also expanded in all directions. Therefore, it can be assumed that the Universe consisted of a homogeneous cloud of these mixed gases, which became increasingly rarefied, filling an ever-increasing volume of space as the Universe expanded. However, this cloud did not retain the same density and did not remain homogeneous. So, the initially homogeneous mixture of hydrogen and helium thickened over time into huge clouds of gas, separated from each other by an almost complete vacuum. These huge in mass and volume gas clouds, which in our view are associated with entire galaxies or with a cluster of galaxies, we could call protogalaxies. In the end, the protogalaxies broke up into billions of smaller clouds, between which lay an almost empty space. Each gas cloud has its own gravitational field. A very dense gas cloud must have a gravitational field strong enough to cause the cloud to begin to collapse. In other words, once it starts to shrink, the gas cloud continues to shrink faster and faster. As the compression increases, the pressure and temperature at its center increase. The temperature rises rapidly, and the incandescent cloud begins to glow. Now it is no longer a gas cloud. We have a star. The galaxies that formed were composed exclusively of hydrogen and helium (mostly hydrogen). The stars formed in them, also having a hydrogen-helium structure, were called "stars of the first generation."
supernovae- stars ending their evolution in a catastrophic explosive process.
The term "supernovae" was used to describe stars that flared up much (by orders of magnitude) stronger than the so-called "new stars". In fact, neither one nor the other is physically new, already existing stars always flare up.
9. The solar system, its structure and age
Solar system- a planetary system that includes the central star - the Sun - and all natural space objects revolving around the Sun. It was formed by gravitational compression of a gas and dust cloud about 4.57 billion years ago.
Most of the mass of objects in the solar system falls on the sun; the rest is contained in eight relatively solitary planets that have almost circular orbits and are located within an almost flat disk - the plane of the ecliptic.
The four smaller inner planets are Mercury, Venus, Earth and Mars (also called planets terrestrial group) - consist mainly of silicates and metals. The four outer planets - Jupiter, Saturn, Uranus and Neptune (also called the gas giants) - are much more massive than the terrestrial planets. The largest planets in the solar system, Jupiter and Saturn, are composed mainly of hydrogen and helium; the outer, smaller Uranus and Neptune, in addition to hydrogen and helium, contain methane and carbon monoxide in their atmospheres.
There are two regions in the solar system filled with small bodies. The asteroid belt, located between Mars and Jupiter, is similar in composition to the terrestrial planets, since it consists of silicates and metals. The largest objects in the asteroid belt are the dwarf planet Ceres and the asteroids Pallas, Vesta, and Hygiea. Beyond the orbit of Neptune are trans-Neptunian objects consisting of frozen water, ammonia and methane, the largest of which are Pluto, Sedna, Haumea, Makemake, Quaoar, Orcus and Eris. There are other populations of small bodies in the solar system, such as planetary quasi-satellites and Trojans, near-Earth asteroids, centaurs, damocloids, as well as comets moving through the system, meteoroids and cosmic dust.
The solar wind (a stream of plasma from the Sun) creates a bubble in the interstellar medium called the heliosphere that extends to the edge of the scattered disk. The hypothetical Oort cloud, which serves as a source of long-period comets, can extend to a distance of about a thousand times beyond the heliosphere.
The solar system is part of the Milky Way galaxy.
10. Inner and outer planets, their comparative characteristics
inner planets.
Mercury- one of the smallest non-atmospheric. The surface of Mercury is covered with numerous impact craters up to 1300 km in diameter.
Venus in size and mass it is very close to the Earth, but it rotates in the opposite direction compared to the rest of the planets. Venus is very wrapped dense atmosphere, consisting of carbon dioxide, and in the upper layers of sulfuric acid
Mars. It is the fourth planet from the Sun. Mars has a very rarefied carbon dioxide atmosphere. Low pressure does not allow water to exist, which should evaporate or freeze.
Earth- the third planet from the Sun in the solar system, the largest in diameter, mass and density among the inner planets. Scientific data indicate that the Earth was formed about 4.54 billion years ago, and soon acquired its satellite - the Moon. It is believed that life appeared on Earth 3.5 billion years ago. Approximately 71% of the planet's surface is covered with water, the rest of the surface is occupied by continents and islands.
outer planets, located behind the asteroid belt, the planets of the outer group are very different from the planets of the inner group. They have huge dimensions, low density, large masses, rotate faster, have a powerful atmosphere, gas-liquid shells and a small silicate core. The inner planets are also distinguished by a small number of satellites or their absence.
Weight Jupiter 314 times the mass of the Earth. The magnetic field of Jupiter is 10 times stronger than the magnetic field of the Earth, in addition, Jupiter is surrounded by powerful radiation belts. Jupiter has 4 rings and 16 moons
Saturn- the second largest planet, but has a very low density. Saturn is more of a gas planet. Saturn is known for its rings up to 400 thousand km in diameter.
Uranus larger than the Earth by 4 times and 14.5 times by mass. This is the third planet - a giant, rotates in the direction opposite to the rotation of most planets. Uranus is surrounded by a system of thin rings. Uranus has 26 moons.
Neptune- the smallest of the giant planets, has the highest density among them. In the atmosphere of Neptune, as well as on Jupiter, large vortex structures are visible that change in time. Neptune has a system of rings and 8 satellites on the surface of which there are traces of water-ice volcanism.
Pluto- the ninth planet from the Sun, very different from the giant planets. Pluto has a very elongated elliptical orbit that intersects Neptune's orbit as Pluto orbits the Sun. It has a rarefied atmosphere surrounding the planet's icy surface. The large satellite Charon (diameter 1172 km), consists of a mixture of ice and silicates, and in its rotation around Pluto, it always faces the planet with the same side.
11. The main natural uniqueness of the planet Earth
Earth - unique planet! Like no other planet, ours is covered in green vegetation, a vast blue ocean containing over a million islands, hundreds of thousands of streams and rivers, vast masses of land called continents, mountains, glaciers and deserts that produce a wide variety of colors and textures.
Some forms of life can be found in almost every ecological niche on the surface of the Earth. Even in very cold Antarctica, hardy microscopic creatures thrive in ponds, tiny wingless insects live in patches of mosses and lichens, and plants grow and bloom annually. From the top of the atmosphere to the bottom of the oceans, from the cold part of the poles to the warm part of the equator, life thrives. To this day, no signs of life have been found on any other planet.
Thus, our "normal" processes on Earth are undoubtedly unique among our solar system, and, according to what we know, throughout the universe:
1. She is a habitable planet. This the only planet in the solar system that supports life. All forms of life right from the smallest microscopic organisms to huge land and sea animals.
2. Its distance from the Sun (150 million kilometers) is reasonable to give it average temperature 18 to 20 degrees Celsius. It's not as hot as Mercury and Venus, and not as cold as Jupiter or Pluto.
3. It has an abundance of water (71%) that is not found on any other planet. And which is not found on any of the planets known to us in a liquid state so close to the surface.
4. Has a biosphere that provides us with food, shelter, clothing and minerals.
5. Doesn't have poisonous gases like helium or methane like Jupiter.
6. It is rich in oxygen, which makes possible life on the ground.
7. Its atmosphere acts like a blanket protecting the Earth from extreme temperatures.
Orbits The planets are elliptical with the Sun at one of the foci, although all except the orbits of Mercury and Pluto are nearly circular. All planetary orbits are more or less in the same plane (called ecliptic and determined by the plane of the Earth's orbit). The plane of the ecliptic is only 7 degrees off the plane of the Sun's equator. Pluto's orbit deviates the most from the plane of the ecliptic (by 17 degrees). The diagram above shows the relative sizes of the orbits of the nine planets when viewed from above on the ecliptic (hence they are not round). They all rotate in the same direction (clockwise when looking down from the Sun's north pole; all but Venus, Uranus and Pluto rotate around their axis in the same direction.
The image above shows nine planets with approximately correct relative dimensions(see other similar images and comparison of terrestrial planets or Appendix 2 for more details).
One way to imagine the real dimensions of the solar system is to imagine a model in which all dimensions and distances are reduced by a billion times (1e9). Then the Earth will be about 1.3 cm in diameter (the size of a grape). The moon rotates at a distance of ~30 cm from it. The sun in this case would be 1.5 meters in diameter (about the height of a person) and located at a distance of 150 meters (about a city block) from the Earth. Jupiter is 15 cm in diameter (the size of a large grapefruit) and 5 city blocks from the Sun. Saturn - (the size of an orange) at a distance of 10 blocks; Uranus and Neptune (lemons) - 20 and 30 quarters. A person on this scale would be the size of an atom; and the nearest star is 40,000 km away.
Numerous small bodies that are in the solar system are not shown in the upper illustration: satellites of planets; big number asteroids (small rocky bodies) orbiting the sun, mostly between Mars and Jupiter, but also elsewhere; and comets (small icy bodies) that come and go from the inner solar system in highly elevated orbits and random orientations to the ecliptic. With a few exceptions, the satellites of planets rotate in the same way as their planets and are approximately in the plane of the ecliptic, but this is not always the case for comets and asteroids.
Classification
The classification of these bodies is the subject of much debate.. Traditionally, the solar system was divided into planets(large bodies revolving around the sun), their satellites(or moons, objects of various sizes orbiting planets), asteroids(objects with low density revolving around the Sun) and comets(small icy bodies with highly eccentric orbits). Unfortunately, the solar system turned out to be more complex than expected:- there are several moons larger than Pluto and two larger than Mercury;
- there are several small satellites that are probably captured asteroids;
- comets sometimes fizzle out and become indistinguishable from asteroids;
- objects from the Kuiper Belt and others like Chiron do not fit this pattern so well;
- The Earth/Moon and Pluto/Charon systems are sometimes referred to as "double planets".
The nine bodies traditionally referred to as planets are often further classified as follows:
- by composition:
- earthly or rocky planets: Mercury, Venus, Earth, and Mars:
- The terrestrial planets consist mainly of stone and metal and have relatively high densities, do not rotate strongly, have a solid surface, do not have rings, and the number of satellites is small.
- giant planetsor gas planets: Jupiter, Saturn, Uranus, and Neptune:
- Gas planets are composed primarily of hydrogen and helium and typically have low densities, fast rotations, deep atmospheres, rings, and a large number of satellites.
- Pluto.
- earthly or rocky planets: Mercury, Venus, Earth, and Mars:
- to size:
- small planets: Mercury, Venus, Earth, Mars and Pluto.
- Small planets are less than 13,000 km in diameter.
- giant planets: Jupiter, Saturn, Uranus, Neptune.
- The diameter of these planets is greater than 48,000 km.
- Mercury and Pluto are sometimes represented as least planets (do not confuse with small planets, is the official term for asteroids).
- Giant planets are sometimes also classified as gas giants.
- small planets: Mercury, Venus, Earth, Mars and Pluto.
- by location relative to the sun:
- domestic solar system planets: Mercury, Venus, Earth and Mars.
- external planets of the solar system: Jupiter, Saturn, Uranus, Neptune and Pluto.
- The asteroid belt between Mars and Jupiter is the boundary between the inner and outer solar system.
- by location relative to Earth :
- domestic planets: Mercury and Venus.
- closer to the sun than the earth.
- These planets, when viewed from Earth, have phases similar to those of the moon.
- Earth.
- external planets: from Mars to Pluto.
- farther from the Sun than Earth.
- These planets always seem to be full or so.
- domestic planets: Mercury and Venus.
- by history:
- classical planets: Mercury, Venus, Mars, Jupiter, Saturn.
- known since prehistoric times
- visible to the naked eye
- modern planets: Uranus, Neptune, Pluto.
- are currently open
- only visible through a telescope
- Earth.
- classical planets: Mercury, Venus, Mars, Jupiter, Saturn.
Images
Comment: most of the images in Nine Planets do not convey the exact color of the object. Most of them were created by combining several black and white images taken through various color filters. While the colors look "real" enough, they're not exactly what you see them.- Montage of Nine Planets (large version on top) 36k jpg
- Another size comparison (from LANL) 93k gif
- Sun and major planets, comparison (from Extrema) 41k gif
- Earth and small bodies, comparison (from Extrema) 35k gif
- Voyager 1 solar system mosaic from 4 billion miles away 36k jpg ; 85k gif (caption)
- Voyager 1 image of 6 planets from 4 billion miles away 123k jpg ; 483k gif
- Pale Blue Dot, a reflection of the above images by Carl Sagan.
More general overview
- History of the discovery of the solar system
- Solar system. Introduction from LANL
- Solar System Family Portrait from NSSDC
- The Life of the Solar System, interactive information from the web.
- Our solar system from NASA Spacelink
- Notes on Far Distant Solar System Objects (from RGO)
- planetary surface temperature notes (from RGO)
- scaled models of the solar system
- Scaled Model of the Solar System Meta Page (links to others)
- Lakeview Museum Community Solar System, the world's largest scaled model of the Solar System from LPI
- Sagan Planet Walk in Ithaca, NY
- Construction of the Solar System, computation of scaled models
- Silver City, NM
- Solar System Walk in Gainesville, Florida
- PlanetTrek, a scaled model of the solar system
- Walking the Solar System, a visual size calculation for comparison from the Exploratorium
Page 16 of 38
Outer planets of the solar system
The outer planets differ significantly in mass, composition and structure from the inner planets. They have a low average density (0.7–1.7 g/cm3), which is determined by their gas composition. The gas envelopes of the outer planets are mainly composed of hydrogen and helium. Also, all these planets have a large number of satellites.
Jupiter is the largest planet in the solar system. Its mass is 31 times the mass of the Earth and 2.3 times the mass of all the other planets combined. Almost all of Jupiter's mass is cooled solar matter. Therefore, the average density of Jupiter is 1.3 g / cm 3, which slightly exceeds the density of water. It is believed that the planet consists of a central core with a mass of 40 Earth masses, which is composed of solid stone material in a compacted state. Next comes a vast zone consisting of hydrogen. The inner part of this zone from the center of the planet to 40,000 km is under a pressure of 3 million atmospheres and at a temperature of 10,000 K. Under these conditions, hydrogen is in a liquid state and acquires the structure of a metal. Electric currents, arising in it, create a powerful magnetic field of the planet.
The outer shell extends up to 70,000 km and is also composed of liquid hydrogen. Above it is the actual atmosphere of Jupiter, consisting of hydrogen, helium, methane and ammonia. The thickness of the atmosphere is 1000 km. Jupiter's large family of moons (15) represents the solar system in miniature. At the same time, the average density of satellites depends on the distance from Jupiter, confirming a pattern common to the solar system.
Saturn is the second largest planet. It has the lowest density of all the planets (0.7 g/cm3), which indicates its predominantly gaseous composition. Since a day on the planet is only
10 o'clock, due to the rapid rotation of Saturn is strongly compressed at the poles. The internal structure of Saturn is about the same as that of Jupiter. The most remarkable property of Saturn are the rings that surround the planet in the equatorial plane. They consist of fine stone material covered with ice. It is assumed that the rings are the remnants of the protoplanetary swarm from which the satellites of Saturn arose (there are 17 of them in total).
Uranus and Neptune - more distant and less studied planets. They have a higher density than Saturn, so they have more substances, heavier than hydrogen and helium. These planets have cores with a diameter of 16,000 km, which are surrounded by mantles consisting of ice, and gaseous shells of hydrogen with an admixture of methane. Uranus and Neptune also have satellites, but we know almost nothing about them.
Pluto - the most distant minor planet that is not part of the family of gas giants. Its dimensions are commensurate with the moon. The temperature on its surface is only 50 K, so all gases, except for hydrogen and helium, are frozen out there. It is believed that the surface of the planet consists of methane ice. In 1978, Pluto's satellite, Charon, was discovered. Just like the Earth with the Moon, Pluto and Charon represent a double planetary system. Interestingly, the mass of Charon is 1/10 of the mass of Pluto, which is the highest in the solar system.
| Table of contents |
|---|
| Structural levels of matter organization. Mega- and macrocosm. |
| Didactic plan |
| Foreword |
| Structural and systematic matter |
| Micro, macro and mega world |
| Basic ideas about the megaworld |
| Origin of the Universe. The Big Bang Theory |
| Expanding Universe Model |
| Formation of the solar system |
| The problem of the existence and search for extraterrestrial civilizations |
| The main directions of the search for extraterrestrial civilizations |
| Modern analysis of the problem of extraterrestrial civilizations |
| solar system |
| galaxies |
| Planets of the solar system |
| Outer planets of the solar system |
| terrestrial planets |
| Comparative characteristics of the terrestrial planets |
| Hypotheses about the origin of the planets of the solar system |
| The shape and dimensions of the Earth |
| Modern ideas about the structure of the Earth |
| Earth formation |
| Age of the Earth |
| Geospheres of the Earth |
solar system
According to the scientific hypothesis, our system was formed from a dark cloud of gas and dust 4.6 billion years ago. As a result of powerful transformations, the cloud turned into a young system with a central yellow star, planets, asteroids and various cosmic bodies.
The structure of the solar system
Our system includes a star of medium brightness - the Sun, and 8 classical planets that revolve around it in elliptical orbits at different distances. It is noteworthy that until 2006 there were 9 planets in the system, the last was Pluto. However, due to new discoveries, Pluto was reclassified, and as a result, it acquired the status of a dwarf planet along with Ceres, Eris and other similar objects.
K, Pluto has a satellite, Charon, which is half the size of a dwarf planet. A further reclassification of Pluto into a double planet is being considered, but today there is not enough information on the structure of the cosmos for such a classification.
The inner and outer planets are separated by an asteroid belt.
What are inner planets
The planets of the system are divided into small warm (inner) and cold gas supergiants (outer). The first type includes Mercury, Venus, Mars and Earth. To the outer - Yuriter, Saturn, Uranus, Neptune. The inner planets have a solid core and consist of metals, gases (oxygen, hydrogen and others), and other heavy elements. The largest are Earth and Venus with sizes of 1 and 0.81, respectively. Earth and Mars have satellites. In particular, the "blue" planet has the Moon, the "red" planet has Phobos and Deimos, which translates as "fear" and "horror". This name of the satellites of Mars is due to the fact that the object was named after the god of war Mars (aka Ares).
The inner planets are much smaller than the gas giants.
The inner and outer planets are separated by a wide asteroid belt that extends between Mars and Jupiter. Unlike gas giants, rocky planets do not have rings made up of asteroid debris, gas, and dust. The smallest Uranus is 14 times larger than the largest "warm" planet - the Earth.
IN scientific world it is believed that on Earth-like planets the possibility of the emergence or presence of life is higher than on gas giants. largely due to the favorable climate and internal structure such planets. In this regard, the search for such space objects is given increased attention by astronomers and scientists.
inner planets terrestrial planets closest to the Sun 4 large planets - Mercury, Venus, Earth, Mars - having a number of similar physical characteristics. See planets.
Big soviet encyclopedia. - M.: Soviet Encyclopedia. 1969-1978 .
See what the "Inner planets" are in other dictionaries:
Solar system Mercury, Venus, Earth and Mars. They are also called terrestrial planets, in contrast to the outer planets of the giant planets. According to a number of cosmogonic theories, in a significant part of the extrasolar planetary systems, exoplanets also ... ... Wikipedia
- ... Wikipedia
- (late Latin, singular planeta, from Greek astèr planétes wandering star) large celestial bodies moving around the Sun and glowing with reflected sunlight; the dimensions and masses of P. are several orders of magnitude smaller than those of the Sun. ... ... Great Soviet Encyclopedia
Comparative sizes of terrestrial planets Terrestrial planets four planets ... Wikipedia
Gas giants compared to the Sun Gas planets (giant planets, gas giants) are planets that have a significant proportion of gas in their composition (mainly hydrogen and helium). In the solar system, this is Jupe ... Wikipedia
Inner and outer planets. The configurations of the planets The movements of the Sun and the planets in the celestial sphere reflect only their visible, that is, the movements that seem to the earthly observer. Moreover, any movements of the luminaries in the celestial sphere are not associated with ... ... Wikipedia
The sun and the celestial bodies revolving around it 9 planets, more than 63 satellites, four rings of giant planets, tens of thousands of asteroids, a myriad of meteoroids ranging in size from boulders to dust particles, as well as millions of comets. IN… … Collier Encyclopedia
Image of the solar system from the book by Andreas Cellarius Harmonia Macrocosmica (1708) The heliocentric system of the world is the idea that the Sun is the central celestial body around which the Earth and others revolve ... Wikipedia
Main article: Cosmogony celestial bodies. They proceed from the concept of the initial state of matter, which fills the entire space, which has known properties, ... ... Wikipedia
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