Solar System small part of a giant molecular giant molecular cloud. cloud.[1] Most Most of the colla collapsi psing ng mass mass colle collecte cted d in the centr centre, e, formforming the Sun Sun,, while the rest flattened into a protoplanetary disk tary disk of of loose dust, out of which the planets the planets,, moons moons,, asteroids,, and other Solar System bodies formed. asteroids This This wide widely ly accept accepted ed model model,, known known as the nebular hypothesis,, was hypothesis was first first deve develo loped ped in the 18th (1700’ (1700’s) s) century by Emanuel by Emanuel Swedenborg, Swedenborg, Immanuel Kant, Kant, and Pierre-Simon Laplace. Laplace. Its subsequent subsequent development development has interwoven interwoven a variety of scientific scientific disciplines disciplines including astronomy,, physics astronomy physics,, geology geology,, and planetary and planetary science. science. As our knowledge of space has grown, the models have been changed to account for the new observations.
Planets and dwarf and dwarf planets of of the Solar System. Compared with each other, the sizes are correct, but the distances are not
The Solar System is the Sun the Sun and and all the objects in orbit in orbit around around it. The The Sun is orbite orbited d byplanets by planets,, asteroids asteroids,, comets and other things.
The Solar System has evolved considerably since its initial formation. formation. Many moons have formed formed from circling circling discs of gas and dust around their parent planets, while other moons are believed to have formed independently and later been captured captured by their their planets. planets. Still Still others, as the Earth the Earth's 's Moon Moon,, may be the result of giant collisi collisions ons..
The Sun is a star star.. It contains contains 99.9 percent percent of the Solar System’s mass System’s mass.. This means that it has strong gravity strong gravity.. The other objects are pulled into orbit around the Sun.
Many collisions between bodies have occurred, and have been important to the evolution of the Solar System. The positions of the planets often shifted, and planets have switched places. [2][3] This planetary This planetary migratio migration n is thought to have been responsible for much of the Solar System’s early evolution.
There are eight planets planets in in the Solar System. System. From closclosest to farthest from the Sun, they are: Mercury, Mercury, Venus Venus,, Earth,, Mars Earth Mars,, Jupiter, Jupiter, Saturn Saturn,, Uranus Uranus and and Neptune Neptune.. The first four planets are called terrestrial planets. planets. They They are are mostl mostly y made made of rock and metal metal,, and and they they are mostl mostly y solid solid.. The last last four plane planets ts are call called ed gas gian giants ts.. This This is becaus becausee they are large planets that are mostly made of gas gas.. Even though they are made of gas, they have much more mass than the terrestrial planets.
2
The Solar System also contains contains other things. things. There There are asteroids,, mostly between Mars and Jupiter. Further out asteroids than Neptune, there is the Kuiper the Kuiper belt and belt and the the scattered disc.. These disc These areas areas have have dwarf dwarf planets, planets, including Pluto Pluto.. There are thousands of very small objects in these areas. Also there there are also comets comets,, centaurs, centaurs, and there is interplanetary interplane tary dust dust..
The Earth’ Earth’ss orb orbit it around around the Sun is nearl nearly y a perf perfec ectt circ circle le,, but when mapped it is foun found d that the Earth the Earth moves moves around the Sun in a very slightly oval shaped, called an elliptical orbit.. The other orbit other planets planets in in the Solar System also circle the Sun in slightly elliptical orbits. Mercury has Mercury has a more elliptical orbit than the others, and some of the smaller objects orbit the Sun in very eccentric very eccentric orbits. orbits.
Six of the planets and three of the dwarf planets are orbited by moons by moons.. Furthermo Furthermore, re, planetary planetary dust orbits dust orbits the gas giants. giants. There There are many other systems other systems like like the Solar System System in the unive universe rse.. Each Each star star has the potent potentia iall to have have a planetary system. There are more than 200 billion 200 billion stars stars in the Milky the Milky Way galaxy. galaxy .
1
Eart Earth’ h’ss orbi rbit
3
Discov Discovery ery and explora exploratio tion n
For For thou thousa sand ndss of year years, s, peop people le had had no need need for a name name for the “Solar System”. System”. They They thought thought the Earth stayed stayed still at the center of everything (geocentrism ( geocentrism). ). Althoug Although h the Greek philosopher philosopher Aristarchus Aristarchus of Samos suggested Samos suggested that there was a special order in the sky, [4] Nicolaus Copernicus was nicus was the first to develop a mathematical a mathematical system that system that described what we now call the “solar system”. This was
Evol Ev oluti ution on of the Solar Solar System System
The formation and evolution and evolution of of the Solar System began 4.6 billion 4.6 billion years years ago with the gravitational collapse gravitational collapse of a 1
2
6
call called ed a new new “sys “system tem of the world world”. ”. In the 17th 17th cencentury, Galileo tury, Galileo Galilei, Galilei , Johannes Kepler and Kepler and Isaac Isaac Newton began helping people understand physics more clearly. This made people slowly accept the idea that the Earth is a planet and moves around the Sun, and that the planets are worlds with the same physical laws that control Earth. More recentl recently, y, telesc telescopes opes and spacecraf spacecraftt have have led to discoveries of mountains of mountains and and craters craters,, and seasonal and seasonal meteorological phenomena such as clouds, clouds, dust storms and ice and ice caps on caps on the other planets.
5
Dwar Dwarff plan planet etss
Pluto had had been been call called ed a plane planett sinc sincee it was was disco discovvered in 1930, but in 2006 astronomers astronomers meeting at the Internationall Astronomi Internationa Astronomical cal Union Union decided decided on the definition of a planet, and Pluto did not fit. Instead they defined defined a new category of dwarf of dwarf planet, planet, into which Pluto did fit, along along with some others. These These small planets planets are somesometimes called plutinos called plutinos.. •
Pluto
•
Ceres
•
Haumea
•
Eris
•
Makemake
6
Planetary distances, not to scale
Struc tructu turre
There There are a few main main parts parts of the Sol Solar ar System System.. Here Here they they are in orde orderr from the Sun Sun,, with with the plane planets ts num number bered, ed, and and the dwarf the dwarf planets marked planets marked with the letters a - e. •
4
STR STRUCTUR UCTURE E
The The eigh eightt plan planet etss
In their order from the Sun:
Terrestrial planets region planets region contains the four planets closest to the sun, all are rocky planets •
(1) Mercury
•
(2) Venus
•
(3) Earth
•
(4) Mars
1. Mercury 2. Venus •
Asteroid belt region belt region contains;
3. Earth •
4. Mars •
Ceres (the (the only dwarf planet in this (a) Ceres region) Asteroids
5. Jupiter •
Gas giant planets region planets region contains;
6. Saturn 7. Uranus 8. Neptune The planets are the biggest objects that go around Sun. It took people many years of looking carefully through telescopes to telescopes to find the objects objects that were farthest farthest away. No one expects to find new planets, planets, but more small objects are found found every every year. Most of the planets planets have moons have moons that orbit around them just as the planet orbit the Sun. There are at least 173 of these moons in the solar system.
•
•
(5) Jupiter
•
(6) Saturn
•
(7) Uranus
•
(8) Neptune
Kuiper belt region belt region contains; •
(b) Pluto
•
(c) Haumea
•
(d) Makemake
6.2
•
•
•
3
Plane Plane of the ecliptic ecliptic
Kuiper belt ob objects jects and possibl possibly y other other dwarf planets short-period comets short-period comets
scattered disc region disc region contains; • •
(e) Eris
Scattered disk objects and objects and possibly other dwarf planets
Sometimes the Outer solar system is taken to mean the Gas Giant Planets, Planets, the Kuiper Belt, Belt, and the Scattered Disk.. But with discoveries Disk discoveries of many objects in the Kuiper the Kuiper Belt,, and the Scattered Belt the Scattered Disk, Disk, and with more dwarf planet discoveries, the Outer solar system is now usually defined more narrowly. The Oort cloud is separate from from the Trans-Neptune region, and much farther out.
6.2 •
•
6.1 6.1
long-period comets long-period comets
Inne Innerr sola solarr syst system em,, Oute Outerr solar solar syst system em,, Trans-Neptune region
The plane of the ecliptic is defined by the Earth’s orbit around the Sun. All of the planets orbit the Sun roughly around this same plane. The farther farther away from this plane a plane planett orbi orbits, ts, the more more inclined is its orbit orbit to the eclip ecliptic tic.. If you could look at the solar system “edge on” then all the planets would be orbiting in the plane of the ecliptic plane.
7
The inner planets. planets. From From left left to right: right: Mercury , Mercury , Venus Venus , , Earth , and Mars Mars
Sometimes people use alternative names for similar regions defined above. These are less formal, and less well defined. •
•
Inner solar system contains •
Terrestrial planets
•
Asteroid belt
Outer solar system contains •
•
Plane Plane of the eclip eclipti ticc
Oort cloud region cloud region contains
Gas giant planets
Ref Referen erence cess
[1] Bouvier, Audrey and Meenakshi Wadhwa, “The age of the solar system redefined by the oldest Pb-Pb age of a meteoritic inclusion”. inclusion”. Nature Geoscience, Nature Publishing Group, a division of Macmillan Publishers Limited. Published online 2010-08-22, retrieved 2010-08-26, doi: 10.1038/NGEO941. Date Date base based d on olde oldest st incl inclus usio ions ns fou ound nd to date date in meteorites,, thought to be among the first solid material meteorites to form in the collapsing solar nebula. [2] R. Gomes, Gomes, H.F. H.F. Levis Levison, on, K. Tsigan Tsiganis, is, A. Morb Morbid idell ellii (2005). “ (2005). “Origin Origin of the cataclysmic Late Heavy Bombardment period of the terrestrial planets” (PDF). planets” (PDF). Nature 435 (7041): 466. . . http://www.nature.com/nature/journal/ v435/n7041/pdf/nature03676.pdf.. v435/n7041/pdf/nature03676.pdf [3] A. Morbidel Morbidelli, li, J. Chambers, Chambers, J.I. Lunine, J.M. Petit, F. Robert, Robert, G.B. Valsec Valsecchi, chi, K.E. Cyr (2000). (2000). “Source “Source regions regions and timescales timescales for for the delivery delivery of water water to the Earth”. Meteoritics & Planetary Science 35: 35: 1309. . [4] WC Rufus. Rufus. “The astronomical system system of Copernicus”. Copernicus”. : 510. 51 0. http://adsabs.harvard.edu/ Popular Astronomy 31: 31 full/1923PA.....31..510R.. Retrieved 2009-05-−09. full/1923PA.....31..510R
Trans-Neptune region contains •
Kuiper belt
•
Scattered disc
8
More More read readiing •
The first four planets closest to the Sun are called the inner planets. They are small and dense terrestrial planets, with solid solid surface surfaces. s. They They are made up of mostly mostly rock and metal with a distinct internal structure and a similar size. size. Three Three also have have an atmosphere. atmosphere. The stud study y of the four planets gives information about geology about geology outside outside the Earth.
9
Lang, Kenneth R. (2011). The Cambridge guide to (2nd ed.). Cambridge Cambridge Universi University ty the Solar System (2nd Press. ISBN 9780521198578
Othe Ot herr we webs bsit ites es •
Views of the Solar System
4
9
•
Your Weight on Other Worlds
•
Solar System Citizendium System Citizendium
OTHE OTHER R WEBSI WEBSITES TES
5
10
Text Text and and image image sources, sources, contr contribut ibutors, ors, and licen licenses ses
10. 10.1 •
Solar Solar System System Source: https://simple.wikipedia.org/wiki/Solar_System?oldid=5180951 Contributors: Angel Angela, a, Menchi Menchi,, Hashar Hashar-Bot~simplewiki, Fennec~simplewiki, Niteowlneils~simplewiki, Jusjih, Bluemask, Guanabot~simplewiki, Netoholic, Gerrit, Blockinblox, Freshstart, Billz, A7x, Roussu, Ionius Mundus, JAnDbot, Lord Patrick~simplewiki, Patrick~simplewiki, Creol, Berek, W7bot, TXiKiBoT, VolkovBot, VolkovBot, Chenzw, Ckatz, Synthebot, NigelJBot, DoraConan~simplewiki, Microchip08, BotMultichill, Panda Bear, OKBot, AlleborgoBot, Exert, SieBot, Liam.gloucester, Barliner, PipepBot, Cometstyles, Fairfield, PixelBot, Idioma-bot, Alexbot, The Flying Spaghetti Monster, SwirlBoy39, Maximillion Pegasus, Pegasus, Fr33kman, Claimgoal, MelancholieBot, SilvonenBot, SilvonenBot, Mdd, EoGuy, LinkFA-Bot, Minor Contributer, Djsasso, Mercy, Synergy, David0811, Tholly, Bluegoblin7, Amirobot, Terryblack, RussBot, Auntof6, NonvocalScream, Ptbotgourou, Thollybot, Jotterbot, Techman224, Art LaPella, TinucherianBot II, TechBot, SteveBot~simplewiki, Aled~simplewiki, ArthurBot, Barras, Xqbot, DirlBot, GoblinBot4, Gordonrox24, Mentifisto, EhJJ, RibotBOT, Pmlineditor, BrianDempsey, Ruy Pugliesi, Rameshngbot, Macdonaldross, Jim.henderson, Alumnum, TobeBot, RedBot, DSisyphBot, Dinamik-bot, Lauryn Ashby, KamikazeBot, PiRSquared17, Yortzec, Clementina, Belinda, Gerakibot, GrouchoBot, AJona1992, Kansan, Ratspeed, EmausBot, Grunny, Savh, ZéroBot, The Three Headed Knight, Goodvac, Alpha Quadrant, Hydriz, HRoestBot, September 1988, Thrasymedes, WikitanvirBot, Mjbmrbot, Mjbmrbot, DerekTK, Morgankevinj AWB, Mh7kJ, SEPTActaMTA8235, MerlIwBot, Mukkakukaku, Wiki13, Vagobot, PhnomPencil, Zedshort, Osiris, Fylbecatulous, Chip123456, Dexbot, Bellabailey, Addbot, Glaisher, Trailblazers325, Atcovi, OneZillionYears, Einsbor, IOSJae, LalaKnows, Castiblanco and Anonymous: 107
10.2 10.2 •
•
•
•
•
Imag Images es
File:Commons-logo.svg Source: https://upload.wikimedia.org/wikipedia/commons/4/4a/Commons-logo.svg License: Public domain Contributors: This version version created by Pumbaa, Pumbaa, using using a proper proper partial circle circle and SVG geometry feature features. s. (Former (Former versions versions used to be slightly warped.) Original artist: SVG version was created by User:Grunt and cleaned up by 3247 3247,, based on the earlier PNG version, created by Reidab by Reidab.. File:Planets2008.jpg Source: https://upload.wikimedia.org/wikipedia/commons/c/c4/Planets2008.jpg License: Public domain Contributors: Edit Edit of en:Image:Planets2006.jpg of en:Image:Planets2006.jpg.. Original was at: http://sse.jpl.nasa.gov/planets/index.cfm Original artist: Edits by Farry by Farry.. Source Source image on English Wikipedia credited by original uploader to “Martin Kornmesser”, and later an anonymous edit re-credited it to “zaria mayers” . File:Terrestrial_planet_size_compar File:Terrestrial_planet_size_comparisons.jpg isons.jpg Source: https://upload.wikimedia.org/wikipedia/commons/b/b9/Terrestrial_planet_ size_comparisons.jpg License: Public domain Contributors: http://solarsystem.nasa.gov/multimedia/gallery/terr_sizes.jpg Original artist: wikipedia user Brian0918 user Brian0918 File:Uklad_Sloneczny_2006 File:Uklad_Sloneczny_2006.png .png Source: https://upload.wikimedia.org/wikipedia/commons/2/2f/Uklad_Sloneczny_2006.png License: CC-BY-SA-3.0 Contributors: ? Original artist: ? File:Wikibooks-logo-en-noslogan.svg Source: https://upload.wikimedia.org/wikipedia/commons/d/df/Wikibooks-logo-en-noslogan. svg License: CC BY-SA 3.0 Contributors: Own work Original artist: User:Bastique User:Bastique,, User:Ramac User:Ramac et et al.
10.3 10.3 •
Text
Conten Contentt lice license nse
Creativee Commons Attribution-Share Creativ Attribution-Share Alike 3.0
