Lecture 4 2016 - open.conted.ox.ac.uk (beta)open.conted.ox.ac.uk/sites/open.conted.ox.ac.uk... · Dwarf Planets! Moons! Small Bodies Elizabeth Charlton, 2016 ... Pluto!Haumea!Makemake

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Solar System I – The Inner Terrestrial Planets and the Asteroid Belt

1 Elizabeth Charlton, 2016



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!  What do we mean by solar system !  “solar” = related to the sun !  solar system

"  all objects gravitationally bound to sun "  region of space dominated by sun's gravity


!  What do you think? !  Sun !  Planets !  Dwarf Planets !  Moons !  Small Bodies


!  the “large” bodies in orbit around the sun "  large enough that gravity forms them into a sphere "  not large enough to become a star

"Mercury in color - Prockter07 centered" by NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington. Edited version of Image:Mercury in color - Prockter07.jpg by Papa Lima Whiskey. - NASA/JPL [1]. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Mercury_in_color_-_Prockter07_centered.jpg#/media/File:Mercury_in_color_-_Prockter07_centered.jpg

"Jupiter New Horizons" by NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute - National Aeronautics and Space Administration. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Jupiter_New_Horizons.jpg#/media/File:Jupiter_New_Horizons.jpg "Neptune Full" by NASA - JPL image. Licensed

under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Neptune_Full.jpg#/media/File:Neptune_Full.jpg


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!  is in orbit around the Sun,

!  has sufficient mass so that it assumes a hydrostatic equilibrium (nearly round) shape, and

!  has“cleared the neighborhood" around its orbit.

2006-International Astronomical Union

"Euler diagram of solar system bodies" by SounderBruce (translated version), Ariel Provost (French version), Tahc (original version) - Derivative work of File:Diagramme d'Euler des corps du Système solaire.svg, translated from French to English. Licensed under CC BY-SA 3.0 via Commons - https://commons.wikimedia.org/wiki/File:Euler_diagram_of_solar_system_bodies.svg#/media/File:Euler_diagram_of_solar_system_bodies.svg


Terrestrial !  Mercury !  Venus !  Earth !  Mars

Jovian !  Jupiter !  Saturn !  Uranus !  Neptune

"Mars 23 aug 2003 hubble" by NASA, ESA, and The Hubble Heritage Team (STScI/AURA) - http://hubblesite.org/newscenter/archive/releases/2005/34/image/j/ (image link). Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Mars_23_aug_2003_hubble.jpg#/media/File:Mars_23_aug_2003_hubble.jpg

"Venus-real color" by NASA or Ricardo Nunes - http://www.astrosurf.com/nunes/explor/explor_m10.htm. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Venus-real_color.jpg#/media/File:Venus-real_color.jpg

"Jewel of the Solar System" by NASA/JPL-Caltech/SSI/Cornell - JPEG File: http://www.nasa.gov/mission_pages/cassini/multimedia/pia17474.html#.Um1oeeig5w0Full-Resolution TIFF: JPL Photojournal PIA17474: Jewel of the Solar System (NASA). Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Jewel_of_the_Solar_System.jpg#/media/File:Jewel_of_the_Solar_System.jpg

"Uranus2" by NASA/JPL-Caltech - http://web.archive.org/web/20090119235457/http://planetquest.jpl.nasa.gov/milestones_show/slide1.html (image link)http://photojournal.jpl.nasa.gov/catalog/PIA18182 (image link). Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Uranus2.jpg#/media/File:Uranus2.jpg 8 Elizabeth Charlton, 2016

!  Pluto !  Eris !  Ceres !  Haumea !  Makemake

"PIA19562-Ceres-DwarfPlanet-Dawn-RC3-image19-20150506" by NASA/JPL-Caltech/UCLA/MPS/DLR/IDA - http://photojournal.jpl.nasa.gov/jpeg/PIA19562.jpg. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:PIA19562-Ceres-DwarfPlanet-Dawn-RC3-image19-20150506.jpg#/media/File:PIA19562-Ceres-DwarfPlanet-Dawn-RC3-image19-20150506.jpg

"Nh-pluto-in-true-color 2x JPEG" by NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute - http://pluto.jhuapl.edu/Multimedia/Science-Photos/image.php?gallery_id=2&image_id=243. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Nh-pluto-in-true-color_2x_JPEG.jpg#/media/File:Nh-pluto-in-true-color_2x_JPEG.jpg

"Eris and dysnomia2" by NASA, ESA, and M. Brown - http://www.nasa.gov/mission_pages/hubble/news/eris.html . Originally uploaded to en.wikipedia by en:User:Serendipodous. For more information, see the description page. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Eris_and_dysnomia2.jpg#/media/File:Eris_and_dysnomia2.jpg

"2003 EL61 Haumea, with moons" by CalTech, Mike Brown et al. - Keck Telescope, CalTech. Licensed under Fair use via Wikipedia - https://en.wikipedia.org/wiki/File:2003_EL61_Haumea,_with_moons.jpg#/media/File:2003_EL61_Haumea,_with_moons.jpg

"Makemake hubble" by NASA - Hubble Space Telescope - Email from Mike Brown (discoverer of Makemake), December 5, 2008. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Makemake_hubble.png#/media/File:Makemake_hubble.png


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!  satellite – any object in gravitational orbit around another larger object

!  moon – natural satellite of a planet

!  “The Moon” – the natural satellite of the Earth


"FullMoon2010" by Gregory H. Revera - Own work. Licensed under CC BY-SA 3.0 via Commons - https://commons.wikimedia.org/wiki/File:FullMoon2010.jpg#/media/File:FullMoon2010.jpg

"Jupiter family" by NASA/JPL - PIA01481This image or video was catalogued by Jet Propulsion Laboratory of the United States National Aeronautics and Space Administration (NASA) under Photo ID: PIA01481.This tag does not indicate the copyright status of the attached work. A normal copyright tag is still required. See Commons:Licensing for more information.Català | Čeština | Deutsch | English | Español | فارسی | Français | Galego | Magyar | Հայերեն | Bahasa Indonesia | Italiano | ⽇本語 | Македонски | മലയാളം | Polski | Português | Русский | Türkçe | 中⽂ | 中⽂（简体）‎ | +/−. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Jupiter_family.jpg#/media/File:Jupiter_family.jpg


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"Asteroidsscale" by NASA/JPL-Caltech/JAXA/ESA - http://dawn.jpl.nasa.gov/multimedia/images/571372main_pia14316-43_800-600.jpg. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Asteroidsscale.jpg#/media/File:Asteroidsscale.jpg

"17pHolmes 071104 eder vga" by Ivan Eder - Ivan Eder. Licensed under CC BY-SA 3.0 via Commons - https://commons.wikimedia.org/wiki/File:17pHolmes_071104_eder_vga.jpg#/media/File:17pHolmes_071104_eder_vga.jpg


!  asteroid – small, rocky, planet-like fragment

!  meteoroid – very small interplanetary rock

!  comet – ice and dust body, eccentric orbit


!  Extends beyond the orbit of Neptune to approximately 50 AU "  Home to many frozen small solar system bodies

!  Pluto !  Haumea !  Makemake

"Kuiper belt plot objects of outer solar system" by WilyD at English Wikipedia. Licensed under CC BY-SA 3.0 via Commons - https://commons.wikimedia.org/wiki/File:Kuiper_belt_plot_objects_of_outer_solar_system.png#/media/File:Kuiper_belt_plot_objects_of_outer_solar_system.png


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!  Populated by icy minor planets and small solar system bodies

!  Due to “scattering” of small bodies by the gas giant planets

!  Unstable "  origin of most periodic comets




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!  How do we measure locations? !  average distance from Sun !  Astronomical Units (AU)

"  average sun-earth distance "  1.5 x 1011 m

!  Heliocentric longitude "  position around the sun


"  Planets all orbit in a disk

"Ecliptic plane 3d view" by Lookang many thanks to author of original simulation = Todd K. Timberlake author of Easy Java Simulation = Francisco Esquembre - Own work. Licensed under CC BY-SA 3.0 via Commons - https://commons.wikimedia.org/wiki/File:Ecliptic_plane_3d_view.gif#/media/File:Ecliptic_plane_3d_view.gif

"Solarsystem3DJupiter" by Lookang many thanks to author of original simulation = Todd K. Timberlake author of Easy Java Simulation = Francisco Esquembre - Own work. Licensed under CC BY-SA 3.0 via Commons - https://commons.wikimedia.org/wiki/File:Solarsystem3DJupiter.gif#/media/File:Solarsystem3DJupiter.gif


!  Mercury 5.8 x 1010 m or 0.38 AU !  Venus 1.1 x 1011 m or 0.72 AU !  Earth 1.5 x 1011 m or 1.00 AU !  Mars 2.2 x 1011 m or 1.50 AU


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"Oort cloud Sedna orbit" by Image courtesy of NASA / JPL-Caltech / R. HurtOriginal text courtesy of NASA / JPL-CaltechSVG conversion by Holek - SVG version of Image:Oort cloud Sedna orbit.jpg, which lists the following sources: [1] [2] Splitzer Space Telescope Released Images about Sedna. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Oort_cloud_Sedna_orbit.svg#/media/File:Oort_cloud_Sedna_orbit.svg 22 Elizabeth Charlton, 2016

!  most asteroids found in one region !  disk from 2.3 AU to 3.3 AU !  between orbits of Mars and Jupiter

!  Ceres 4.15x1011m or 3.0 AU


!  Jupiter 7.8 x 1011 m or 5.2 AU !  Saturn 1.4 x 1012 m or 9.5 AU !  Uranus 2.9 x 1012 m or 19 AU !  Neptune 4.5 x 1012 m or 30 AU

!  Pluto 5.9 x 1012 m or 39 AU !  Eris 1.0 x 1013 m or 68 AU !  Haumea 6.4 x 1012 m or 43 AU !  Makemake 6.9 x 1012 m or 46 AU


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"Oort cloud Sedna orbit" by Image courtesy of NASA / JPL-Caltech / R. HurtOriginal text courtesy of NASA / JPL-CaltechSVG conversion by Holek - SVG version of Image:Oort cloud Sedna orbit.jpg, which lists the following sources: [1] [2] Splitzer Space Telescope Released Images about Sedna. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Oort_cloud_Sedna_orbit.svg#/media/File:Oort_cloud_Sedna_orbit.svg 25 Elizabeth Charlton, 2016

!  Furthest extent of Solar system

!  50,000 AU to 100,000 AU (approximately)

!  sun's gravity just barely enough to hold objects

!  long period comets originate here

"Kuiper belt - Oort cloud-en" by NASAThis SVG image was created by Medium69.Cette image SVG a été créée par Medium69.Please credit this : William Crochot - http://herschel.jpl.nasa.gov/solarSystem.shtml. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Kuiper_belt_-_Oort_cloud-en.svg#/media/File:Kuiper_belt_-_Oort_cloud-en.svg



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!  most objects are spheres (or close to spheres) !  Diameter – distance across object !  Radius – average distance from center out to edge


!  Sun !  radius = 7.0 x 108 m

"  700,000,000 meters "  700,000 km =7.0 x 105 km


!  Planets – 2,400 km to 70,000km !  Dwarf planets – 450 km to 1,200km !  Moons – 5 km to 2,600 km !  asteroids – most < 1 km, up to 525 km !  comets – nucleus up to 100 km !  meteoroids – most in cm range, up to 100 m


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!  Jupiter – largest planet "  7 x 107m (70,000 km)

!  Mercury – smallest planet "  2.4 x 106m (2,400 km)

!  Size order "  Jupiter, Saturn, Uranus,

Neptune, Earth, Venus, Mars, Mercury



!  Sun = 110 !  Jupiter = 11.2 !  Saturn = 9.1 !  Uranus = 4.0 !  Neptune = 3.9

!  Earth = 1.00 !  Venus = 0.95 !  Mars = 0.53 !  Mercury = 0.38

!  Eris = 0.19 !  Pluto = 0.18 !  Makemake=0.10-0.15 !  Haumea=0.11 !  Ceres = 0.07


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"  What are the major characteristics of each of the inner planets?



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!  smallest inner planet !  looks like Moon (gray, bare, cratered) !  essentially no atmosphere



!  a dense CO2 atmosphere, !  covered with deep sulfuric acid clouds, !  hottest planet, !  immense volcanic peaks tower over desolate plains


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"The Earth seen from Apollo 17" by NASA/Apollo 17 crew; taken by either Harrison Schmitt or Ron Evans - http://www.nasa.gov/images/content/115334main_image_feature_329_ys_full.jpgAlt: http://grin.hq.nasa.gov/ABSTRACTS/GPN-2000-001138.html (direct link). Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:The_Earth_seen_from_Apollo_17.jpg#/media/File:The_Earth_seen_from_Apollo_17.jpg 40 Elizabeth Charlton, 2016

!  Great variety: !  blue seas, white clouds and ice caps, red deserts,

green jungles, mountains !  Life!!



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!  Thin CO2 atmosphere !  vast red deserts with craters and dunes, !  polar caps of ice and CO2, !  canyons and dry river beds, !  ancient volcanoes,


!  What do they all have in common? !  What caused these characteristics?


!  have similar sizes and structure "  Iron/nickel core "  Rocky mantle and crust

http://sse.jpl.nasa.gov/multimedia/gallery/terrest_int.jpg


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!  What caused this common structure? "  They are formed in the inner part of the solar system from

the same material "  Solid material formed clumps "  Gases pushed away by the Sun "  Differentiation "  Cooling and cratering


"Terrestrial planet sizes" by NASAMercury image: JHUAPLVenus image: JPLMars image: HST - Mercury Globe-MESSENGER mosaic centered at 0degN-0degE.jpgVenus globe.jpgThe Earth seen from Apollo 17.jpgMars 23 aug 2003 hubble.jpg. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Terrestrial_planet_sizes.jpg#/media/File:Terrestrial_planet_sizes.jpg


!  Memorizing differences is hard and meaningless !  Understanding the reasons gives meaning to the

facts and makes it easier to remember them


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!  Mass and radius affect interior temperature "  Smaller => not as hot internally

!  This in turn determines the level of tectonic activity "  Smaller => not as active

!  Examples: "  Mercury the least active, "  then Mars, "  then Venus and Earth


!  Internal activity affects the surface !  More activity => more lava on the surface !  More lava => features are erased more often

!  Internal activity also affects a planet’s atmosphere !  volcanic gases are the most likely source of gases !  Less activity => less gas


!  Mass and radius affect atmosphere !  Low mass Mercury and Mars will have a smaller

source of gas than Venus/Earth !  the low surface gravity of these small planets also

means they will have trouble retaining the gases they generate

!  Examples: "  Mercury the least atmosphere, "  then Mars, "  Then Venus/Earth


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!  Heating depends on planet’s distance from Sun "  closer => warmer further => cooler

!  Example: "  Mercury daytime side is very hot (~427oC) "  Mars daytime side is much colder (~20oC in Martian

Summer)


!  Heat and high energy light from Sun can alter atmosphere "  Break apart molecules "  Drive off light gases

!  Example: "  Mercury, lost most of the little atmosphere it had "  Venus, UV breaks H2O apart with the H escaping into

space


!  While temperature affects the atmosphere, !  the opposite is also true…

!  Atmosphere affects the temperature: !  Warming by greenhouse effect !  Insulates surface

!  Examples: "  Venus is hottest "  Earth is warmer than Moon (at night)


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!  Atmosphere can affect surface:

!  Protects against impacts !  Wind erosion covers impact craters

!  Examples: "  Mercury, Mars, and Moon many impacts craters "  Earth, Venus, not as many, not as visible


!  The water near Earth’s surface makes possible many chemical reactions not found elsewhere

!  Examples: !  Biological processes !!! !  CO2 removed from atmosphere by dissolving in

water

!  Water also causes large scale erosion


!  photosynthesis !  plants convert H2O and CO2 -> O2

"  Earth’s atmosphere has oxygen

!  Planets cover and break down rocky surface !  Animals (People) shape surface

"  atmosphere !  Sea creatures turn CO2 into rock


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!  Surfaces all started out smooth, !  then shaped by: !  cooling, tectonics, impacts, and erosion

!  they ended up with different surfaces


!  Mars, Venus and Earth started with similar atmospheres "  CO2 with traces of N2 and H2O

!  But were then modified by: !  sunlight, tectonic activity, and, in the case of the

Earth, life


!  Two main factors can be used to explain all of these differences

!  Planetary size

!  Distance from Sun


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!  How would Mercury be different if it was larger? !  How would Mars be different if it was closer to the

Sun?


Elizabeth Charlton, 2016 62

!  remnants of planetisimals !  a small rocky fragment that orbits the sun !  too small to be planet !  doesn't orbit a planet

"(253) mathilde" by NASA - http://nssdc.gsfc.nasa.gov/imgcat/html/object_page/nea_19970627_mos.html. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:(253)_mathilde.jpg#/media/File:(253)_mathilde.jpg


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!  Some mostly rock !  Some mostly iron !  Some are a mixture of rock and iron


"InnerSolarSystem-en" by Mdf at English Wikipedia - Transferred from en.wikipedia to Commons.. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:InnerSolarSystem-en.png#/media/File:InnerSolarSystem-en.png


Lecture 4 2016 - open.conted.ox.ac.uk (beta)open.conted.ox.ac.uk/sites/open.conted.ox.ac.uk... · Dwarf Planets! Moons! Small Bodies Elizabeth Charlton, 2016 ... Pluto!Haumea!Makemake

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