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Coleen Morete

8/9/2019 Coleen Morete

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MEMBERS OF THE SOLAR SYSTEM

The Solar System[a] comprises the Sun and the objects that orbit it either direct!" or indirect!"#[b] 

O$ those objects that orbit the Sun direct!" the !ar%est ei%ht are the p!anets[c] that $orm the

 p!anetar" s"stem around it &hi!e the remainder are si%ni$icant!" sma!!er objects such as d&ar$

 p!anets and sma!! So!ar S"stem bodies 'SSSBs( such as comets and asteroids#[d]

The So!ar S"stem $ormed )#* bi!!ion "ears a%o $rom the %ra+itationa! co!!apse o$ a %iant

interste!!ar mo!ecu!ar c!oud# The +ast majorit" o$ the s"stem,s mass is in the Sun &ith most o$

the remainin% mass contained in -upiter # The $our sma!!er inner p!anets Mercur" .enus Earth 

and Mars a!so ca!!ed the terrestria! p!anets are primari!" composed o$ roc/ and meta!# The $our

outer p!anets the %iant p!anets are substantia!!" more massi+e than the terrestria!s# The t&o

!ar%est the %as %iants -upiter and Saturn are composed main!" o$ h"dro%en and he!ium0 the t&o

outermost p!anets the ice %iants 1ranus and 2eptune are composed !ar%e!" o$ substances &ith

re!ati+e!" hi%h me!tin% points compared &ith h"dro%en and he!ium ca!!ed ices such as &ater

ammonia and methane# A!! p!anets ha+e a!most circu!ar orbits that !ie &ithin a near!" $!at disc

ca!!ed the ec!iptic#

The So!ar S"stem a!so contains sma!!er objects#[d] The asteroid be!t &hich !ies bet&een Mars and

-upiter most!" contains objects composed !i/e the terrestria! p!anets o$ roc/ and meta!# Be"ond

 2eptune,s orbit !ie the 3uiper be!t and scattered disc popu!ations o$ trans42eptunian objects 

composed most!" o$ ices and be"ond them a ne&!" disco+ered popu!ation o$  sednoids# 5ithin

these popu!ations are se+era! do6en to possib!" tens o$ thousands o$ objects !ar%e enou%h to ha+e

 been rounded b" their o&n %ra+it"#[78] Such objects are cate%ori6ed as d&ar$ p!anets# 9denti$ied

d&ar$ p!anets inc!ude the asteroid :eres and the trans42eptunian objects ;!uto and Eris#[d]

 9naddition to these t&o re%ions +arious other sma!!4bod" popu!ations inc!udin% comets centaurs 

and interp!anetar" dust $ree!" tra+e! bet&een re%ions# Si< o$ the p!anets at !east three o$ the

d&ar$ p!anets and man" o$ the sma!!er bodies are orbited b" natura! sate!!ites[e] usua!!" termed

=moons= a$ter Earth,s Moon# Each o$ the outer p!anets is encirc!ed b"  p!anetar" rin%s o$ dust and

other sma!! objects#

The so!ar &ind p!asma $!o&in% out&ards $rom the Sun creates a  bubb!e in the interste!!ar

medium /no&n as the he!iosphere# The he!iopause is the point at &hich pressure $rom the so!ar

&ind is e>ua! to the opposin% pressure o$ interste!!ar &ind0 it e

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is !ocated in the Orion Arm ?*888 !i%ht "ears $rom the center o$ the Mi!/" 5a"#

http://en.wikipedia.org/wiki/Orion_Armhttp://en.wikipedia.org/wiki/Milky_Wayhttp://en.wikipedia.org/wiki/Orion_Armhttp://en.wikipedia.org/wiki/Milky_Way