Catalog of abstracts Collection of abstracts on various topics Home RSS of Abstracts Search query
To find
Main
What is the difference between the planets of the inner and outer group Category: Astronomy, Aviation, Cosmonautics
The solar system is a system of celestial bodies consisting of the Sun, 9 major planets and their satellites, tens of thousands of minor planets and their satellites, tens of thousands of minor planets( asteroids), many comets, small meteor bodies and interplanetary gas and dust.
Everything in the solar system is determined by the Sun, which is the most massive body and the only one that owns its own glow.
The sun is an ordinary main sequence star with an absolute magnitude of +5.
Its volume is a million times larger than the volume of the Earth, but compared to the giant stars, the Sun is very small.
Other members of the Solar system shine with reflected sunlight and look so bright in the sky, it is not difficult to forget that for the universe as a whole they are not even remotely as important objects as they seem to us.
Nine planets orbit the Sun in ellipses (not much different from circles) in almost the same plane in order of distance from the Sun: Mercury, Venus, Earth (with the Moon), Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.
The planets are divided into two distinct groups.
The first includes relatively small planets: Mercury, Venus, Earth and Mars, with diameters from 12756 km (Earth) to 4880 km (Mercury).
These planets have some common characteristics.
All of them, for example, have a solid surface and, obviously, consist of a similar substance in composition, although the Earth and Mercury are denser than Mars and Venus.
Their orbits generally do not differ from circular ones, only the orbits of Mercury and Mars are more elongated than those of Earth and Venus.
Mercury and Venus are called inner planets because their orbits lie inside the earth; they, like the Moon, are in different phases — from new to full and remain in the same part of the sky as the Sun.
Mercury and Venus HAVE NO satellites, the Earth has one satellite (the Moon is known to us), Mars has two satellites Phobos and Deimos, both very small and clearly different in nature from the Moon.
On Mars there is a wide gap in which thousands of small bodies are moving, called asteroids, planetoids or small planets.
The diameter of even the largest of them — Ceres is only about 1000-1200 km.
Far beyond the main asteroid zone there are four giant planets: Jupiter, Saturn, Uranus, Neptune.
These planets are completely different from the planets of the Earth group: they are rather gas and liquid
than solid, with very dense atmospheres.
Their mass is so large that they were able to retain most of the original hydrogen.
So, the rotation speed for Jupiter is 60 km / s, while for the Earth it is 11.2 km / s.
Their average distance from the Sun is from 778 million km (Jupiter) up to 4497 million km (Neptune).
The giant planets have a lot in common, but they differ greatly in details.
Their densities are relatively low, and the density of Saturn is even less than the density of water.
Although Jupiter is visible solely due to the sunlight reflected from it, the planet also has its own heat sources.
However, despite the fact that the temperature of its core should be high, it is far from sufficient for nuclear reactions to begin there, so Jupiter cannot be compared with a star like the Sun.
Five planets Mercury, Venus, Mars, Jupiter and Saturn have been known since ancient times, since they are all clearly visible to the naked eye.
All of them are part of the outer group of planets.
Uranus, which is at the limit of visibility with the naked eye, was accidentally discovered in 1781.
All the giants are accompanied by retinues of satellites: Jupiter has 14 satellites, Saturn — 15, Uranus 5 and Neptune 2.
Some of the satellites are the size of planets with diameters at least equal to the diameter of Mercury.
Pluto, itself removed from the known planets, was discovered in 1930.
This is by no means a giant, it is smaller than the Earth in size, and it is usually attributed to the planets of the Earth group, although very little is known about it.
The closer a planet is to the Sun, the greater its linear and angular velocities and the shorter the period of rotation around the Sun.
While the planes of the orbits of most planets are close to the plane of the Earth's orbit (the difference is 7 degrees for Mercury and much less for other planets), the orbit of Pluto is inclined to it relatively strongly — by 17 degrees and is so elongated that at the closest approach to the Sun, Pluto comes closer to it than Neptune.
It is quite likely that Pluto forms its own class of planets; it is even possible that it was once a satellite of Neptune and only later gained independence.
Comets are also members of the Solar System.
These are large formations of rarefied gas and dust particles with a very small solid core, they also orbit the Sun.
Most of them have elliptical orbits that go beyond the orbit of Pluto, so that the diameter of the latter is only conditionally taken as the diameter of the Solar System.
In addition, countless meteor bodies (they can be considered as a kind of garbage in the Solar System, some meteor bodies are definitely associated with comets) are orbiting around the Sun in ellipses, ranging in size from a grain of sand to a small asteroid.
Together with asteroids and comets, they belong to the small bodies of the Solar system.
The space between the planets is filled with extremely rarefied gas and cosmic dust.
It is permeated by electromagnetic radiation; it is a carrier of magnetic and gravitational fields.
The sun is 109 times larger than the Earth in diameter and about 333,000 times more massive than the Earth.
The mass of all the planets is only about 0.1% of the mass of the Sun, so it controls the movement of all the members of the Solar system by the force of its attraction.
Distinctive features of the planets of the Earth group from the giant planets.
Mercury, Venus, Earth and Mars differ from the giant planets in smaller sizes, lower mass, higher density, slower rotation, much more rarefied atmospheres (there is practically no atmosphere on Mercury, so its daytime hemisphere is very hot; all giant planets are surrounded by powerful extended atmospheres), a small number or lack of satellites.
Since the giant planets are far from the Sun, their temperature (at least above their clouds) is very low: on Jupiter — 145 C, on Saturn 180 C, on Uranus and Neptune even lower.
And the temperature of the planets of the Earth group is much higher (on Venus up to plus 500 C).
The low average density of giant planets can be explained by the fact that it comes out by the distribution of mass on the visible volume, and we estimate the volume by the opaque layer of the large atmosphere.
The low density and abundance of hydrogen distinguish the giant planets from other planets.
List of literature
B. A. Vorontsov Velyaminov "ASTRONOMY 11".
Moscow, "EDUCATION" 1989 Encyclopedia (first volume) "Science and the universe".
Edited by A. D. Sukhanov and G. S. Khromov.
Moscow, "MIR", 1983.
Soviet Encyclopedic Dictionary.
Moscow "Soviet Encyclopedia" 1987
Other abstracts of the heading "Astronomy, Aviation, Cosmonautics" The scale of the Universe, the composition and scale of the solar system The composition and scale of the Solar system.
Configurations and conditions of visibility of planets Yuri Vasilyevich Kondratyuk Sikorsky I. I.-Ukrainian aircraft designer Volcanoes of the Solar system A materialistic picture of the world through the eyes of astronomy The Sun is the nearest star Diffuse matter Determination of geographical latitude by astronomical observations Masses and dimensions vision
Recent abstracts The concept of spare parts and their accounting Journalistic word as a means of transmitting the inner state of a person Hamerion narrow leaved, khvilivnik ordinary, horsetail field Period of peaceful development of the revolutionary process in Ukraine Common beans, cumin, common goat bearded meadow Millipede, common bagulnik, badan ordinary rake, urban gravilat, buckwheat, Gritsik, Fenugreek Universal fees Transport movement of goods and passengers Stonehenge Mikhail Khanenko Economic analysis of the bank's activities The scale of the Universe, composition and scale congenital malformations of the solar system on the example of the gorges of the lip and sky Physical culture
after childbirth Customs and rituals of the Ukrainian people for nature protection Historical prerequisites for the emergence of Keynesianism Tests, research and verification of geodetic instruments What is the difference between the planets of the inner and outer group Composition and scale of the Solar system.
Configurations and conditions of visibility of planets Published accounting statements and methods of reading it Constitutionalism and freedom of the press Strawberry forest, suripitsa ordinary Geographical features of the countries of the former Soviet Union The basics of tourism
Copyright © 2010-2017 Catalog of abstracts
