Solar System [] comprises a the Sun and the objects that, orbit it either directly or indirectly. [] Of B those objects that. Orbit the, Sun directly the largest eight are the planets [] that C form the planetary system around it while the, remainder. Are significantly, smaller objects such as dwarf planets and small Solar System bodies such as comets and asteroids.[] Of D those that orbit the, Sun indirectly two are larger than the smallest planet.
The Solar System formed 4.6 billion. Years ago from the gravitational collapse of a giant interstellar molecular cloud. The vast majority of the system s mass. ' Is in, the Sun with most of the remaining mass contained in Jupiter. The four smaller inner planets Mercury Venus Earth,,,, And, MarsAre, terrestrial planets being primarily composed of rock and metal. The four outer planets are giant planets being substantially,, More massive than the terrestrials. The two largest Jupiter Saturn, and, gas, are giants being composed mainly of hydrogen. And helium; the two, outermost planets Uranus and Neptune are ice giants,,Being composed largely of substances with relatively high melting points compared with hydrogen and helium called ices,,, Such as water ammonia and, methane. All planets have almost circular orbits that lie within a nearly flat disc called the. Ecliptic.
The Solar System also contains smaller objects. [] The asteroid, D belt which lies between Mars, and Jupiter mostly. Contains, objects composedLike the terrestrial planets of rock, and metal. Beyond Neptune 's orbit lie the Kuiper belt and, scattered disc populations. Of trans-Neptunian objects composed mostly of ices and beyond, them a newly discovered population of sednoids. Within these. Populations are several dozen to possibly tens of thousands of objects large enough to have been rounded by their own gravity.[] Such 10 objects are categorized as dwarf planets. Identified dwarf planets include the asteroid Ceres and the trans-Neptunian. Objects Pluto and Eris. [] In D addition to these, two regions various other small-body populations including comets centaurs,,, And interplanetary dust freely travel, between regions. Six of, the planets at least three of the, dwarf planetsAnd many of the smaller bodies are orbited by natural satellites, [] usually e termed "moons" after the Moon. Each of the. Outer planets is encircled by planetary rings of dust and other small objects.
The, solar wind plasma flowing outwards. From, the Sun creates a bubble in the interstellar medium known as the heliosphere.The heliopause is the point at which pressure from the solar wind is equal to the opposing pressure of interstellar wind;? It extends out to the edge of the scattered disc. The, Oort cloud which is believed to be the source for, long-period comets. May also exist at a distance roughly a thousand times further than the heliosphere. The Solar System is located in the Orion. ,, Arm 26000 light-years from the center of the Milky Way.
การแปล กรุณารอสักครู่..