Today it seems obvious to us to talk about planets of the sysbut solar as a known entity and the subject of much attention but it has not always been this way. For millennia, all but Earth, of course, have been regarded as an unexplored world. It is thanks to space expeditions but also to probes and researchers in this field that today we can count them, tell them and dream about them. For a long time we had the presumption to believe that in the sky it was only us, Earth, in addition to the Sun and the Moon.
Planets of the solar system
The Solar system is not only made up of the Sun and the planets but there are numerous other celestial bodies to deal with: the satellites of the planets, a thousand comets, an indefinite quantity of meteorites and 1800 planets called asteroids.
What are the planets of system solar ? they are celestial bodies characterized by a cold outer surface, by dimensions much smaller than those of the Stars and by a motion of revolution around the Sun which causes us to see them change position in the sky with respect to the fixed stars. Sure there are Pluto and Mercury which are an exception but for the rest we have planets of the solar system that move around the Sun following elliptical orbits in which one of the two foci is occupied by the Sun. It is not over: in addition to revolution motion the planets also perform a rotational motion, precisely the same motion in which the Earth rotates on itself around an axis of rotation, in our case inclined. Both motions of the planets proceed counterclockwise from West to East.
The movement of the Earth causes the day lasts 24 hours but this only applies to our planet, in general the time taken by the planet to rotate on itself can change from time to time depending on which of the many you are going to consider. Jupiter for example has days of 10 hours, Venus of 243 Earth days.
Planets of the solar system: how many are there
The planets present in the Solar systemthere are nine, they are all characterized by an almost spherical shape and a light reflected from the Sun.
Planets of the solar system: which ones are in order
We start from the planet closest to the Sun and proceed naming them as we move away from it. Here they are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.
Planets of the solar system for children
When we start studying the planets of the solar system as children we divide them into two categories to simplify memorization. There are the planets of guy terrestrial and the planets of jovian type. The first, the terrestrial ones, are characterized by a density 5 times higher than that of water, by an extremely rarefied atmosphere and are mainly made up of rocky materials, metals and minimal quantities of gas. In this category we find the planets that are similar to the Earth like Mercury, Venus, Mars and the Earth itself.
The Jupiter-type planets, on the other hand, have a density 1.2 times higher than that of water and have high percentages of Hydrogen, Helium and "ice". Another difference lies in the atmospheres, these planets have very dense ones, consisting mainly of Hydrogen, Helium, Methane and Ammonia, this partly because of the mass of the Jupiter planets and partly because of their distance from the Sun.
The mass of the planets affects the atmosphere by retaining the molecules of atmospheric gases while the great distance from the sun instead allows the young planets to maintain a low temperature and prevent the gas particles from thermal agitation such as to allow an escape velocity. By exclusion from the category of Jupiter type belong planets similar to Jupiter as the same Jupiter, Saturn, Uranus and Neptune.
As a child, it is perhaps easier to distinguish the planets of the solar system by their position relative to the asteroid zone. There are therefore i inner planets (Mercury, Venus, Earth and Mars) and i outer planets (Jupiter, Saturn, Uranus and Neptune).
Planets in astrology
In Astrology the planets can be divided into four distinct categories. The Luminaries (Sun and Moon) represent the fundamental components of the personality, those that give the most evident imprint to the characteristics of the subject. THE Fast planets (Mercury, Venus and Mars) instead represent those components designed to satisfy the most immediate needs of life, Semi-slow planets (Jupiter and Saturn) and i lenses (Uranus, Neptune and Pluto) are linked to human components that are still under development and over which most of humanity has relatively little control.
Planets of the solar system: books
Also online there are several guides that help us orient ourselves within our vast solar system between planets and other celestial bodies. The most comprehensive is undoubtedly "Stars and planets. The most complete guide to stars, planets, galaxies and the solar system ": collects detailed maps for each of the 88 constellations of the northern and southern hemisphere; data and notes on all the brightest stars and other celestial objects of interest, advice on choosing and using binoculars and telescopes suited to your possibilities, detailed moon maps with descriptions of the main characteristics of the satellite.
He is a bit lazy, he does not want to leaf through any book but does not want to give up exploration, he can buy 3D planetsthat light up in the dark, to hang in your room, or a complete kit that reproduces the solar system, always in 3D and in fluorescent material. Both are for sale on Amazon as well as the book.
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