Physical Properties of PlanetsPhysical Properties of PlanetsPhysical Properties of PlanetsPhysical Properties of Planets

Two distinct types of planets:Two distinct types of planets:Two distinct types of planets:Two distinct types of planets: Terrestrial Planets (Earth-like) Jovian Planets (Jupiter-like)

Size:Size:Size:Size:

Mass:Mass:Mass:Mass:

Physical Property of PlanetsPhysical Property of PlanetsPhysical Property of PlanetsPhysical Property of Planets

Density: - measure of how compressed a substance is - determined by total mass & volume it occupies

ρ = Mass Volume

Examples: Water 1.0 g/cm3 Air 0.0013 g/cm3 Rocks 2.5-3.5 g/cm3 Styrofoam 0.1 g/cm3 Lead 12 g/cm3 Ice 0.92 g/cm3 Gold 19 g/cm3

- indicates the compositioncompositioncompositioncomposition of object! Density:Density:Density:Density:

Terrestrial Planets:Terrestrial Planets:Terrestrial Planets:Terrestrial Planets: - large density ("rocky" composition)

Jovian Planets:Jovian Planets:Jovian Planets:Jovian Planets: - small density ("Gas Giants")

-mostly liquefied gas

PPPProtrotrotrot::::

No. of Moons:No. of Moons:No. of Moons:No. of Moons:

Mercury 0 Jupiter 67+rings Venus 0 Saturn 62+rings Earth 1 Uranus 27+rings Mars 2 Neptune 14+rings

Pluto 5

Terrestrial Terrestrial Terrestrial Terrestrial Planets:Planets:Planets:Planets:

- small size - small mass - large density - "rocky" composition - long rotational periods - hard surfaces with possible atmosphere

-no atmosphere � Mercury

-very, very thick atm. � Venus - few, if any moons

���� All 4 Inner PlanetsAll 4 Inner PlanetsAll 4 Inner PlanetsAll 4 Inner Planets (and(and(and(and some large moons)some large moons)some large moons)some large moons)

Mercury Global ImageMercury Global ImageMercury Global ImageMercury Global Image

Mercury surface close-up

Mercury "Spider Crater"

Mercury and Moon comparison

Venus visual image

Venus Radar Map

Surface of Venus (Venera spacecraft)

Maat Mons volcano from Magellan data

Mars Global Image

Opportunity rover at Endeavour Crater

Ice on Mars (Phoenix Lander)

Ice on Mars (Phoenix Lander)

Subsurface Water on Mars?

Eroded pebbles in sediment = fast flowing water.

Curiosity rover at Gale Crater

Ancient Mars ??

Jovian Planets:Jovian Planets:Jovian Planets:Jovian Planets:

-large size -large mass -small density "Gas Giants" -mostly liquefied gas -short rotational periods -ring systems and many moons

���� All 4 Large Outer PlanetsAll 4 Large Outer PlanetsAll 4 Large Outer PlanetsAll 4 Large Outer Planets

http://solarsystem.nasa.gov/planets/profile.cfm?Object=Jupiter&Display=http://solarsystem.nasa.gov/planets/profile.cfm?Object=Jupiter&Display=http://solarsystem.nasa.gov/planets/profile.cfm?Object=Jupiter&Display=http://solarsystem.nasa.gov/planets/profile.cfm?Object=Jupiter&Display=GalleryGalleryGalleryGallery

Jupiter's Rings discovered by Voyager 1

Voyager 1 image of Saturn

Scattered light seen from behind Saturn (Cassini)

Titan and Epimetheus behind Saturn's rings

(Cassini)

Saturn in infrared

Recent Storm (2010 - now) on Saturn

Enceladus (300 mi across) in front of Saturn

North Pole of Saturn with “Hexagon”

Neptune's rings (Voyager 2)

Neptune and Triton (Voyager 2)

Plutonian (Pluto-like) Objects ---- Small mass, sizeSmall mass, sizeSmall mass, sizeSmall mass, size ---- Small density (mostly ice)Small density (mostly ice)Small density (mostly ice)Small density (mostly ice) ---- Very Elliptical orbitsVery Elliptical orbitsVery Elliptical orbitsVery Elliptical orbits with hwith hwith hwith high inclinationsigh inclinationsigh inclinationsigh inclinations ---- Beyond orbit of NeptuneBeyond orbit of NeptuneBeyond orbit of NeptuneBeyond orbit of Neptune (Kuiper Belt(Kuiper Belt(Kuiper Belt(Kuiper Belt, Oort Cloud, Oort Cloud, Oort Cloud, Oort Cloud))))

PlutoPlutoPlutoPlutoniannianniannian / Dwarf Planets/ Dwarf Planets/ Dwarf Planets/ Dwarf Planets

NameNameNameName aaaa diameterdiameterdiameterdiameter Eris (2003) * 68 AU 1450145014501450 mimimimi Pluto (1930)Pluto (1930)Pluto (1930)Pluto (1930) 39 AU39 AU39 AU39 AU 1430 mi1430 mi1430 mi1430 mi Makemake (2005) 46 AU 1200 mi 2007 OR10 67 AU ~800 mi Haumea (2004) 43 AU ~780 mi Quaoar (2002) 43 AU ~700 mi Sedna (2004) 530 AU ~650 mi Orcus (2004) 39 AU ~610 mi 2002 MS4 41 AU ~600 mi Salacia 42 AU ~575 mi

* * * * http://www.gps.caltech.edu/~mbrown/planetlila/index.html http://www.gps.caltech.edu/~mbrown/dwarfplanets/http://www.gps.caltech.edu/~mbrown/dwarfplanets/http://www.gps.caltech.edu/~mbrown/dwarfplanets/http://www.gps.caltech.edu/~mbrown/dwarfplanets/

Likely Likely Likely Likely Candidates Candidates Candidates Candidates

NameNameNameName aaaa DiameterDiameterDiameterDiameter Varuna (2000) 43 AU ~475 mi 2013 FY27 59 AU ~475 mi 2003 AZ84 40 AU ~465 mi Varda 46 AU ~430 mi Ixion (2001) 40 AU ~420 mi Chaos 46 AU ~380 mi

Formation of the Solar SystemFormation of the Solar SystemFormation of the Solar SystemFormation of the Solar System

Sun, planets and all of solar system -formed from gravitational collapse of large cloud of gas & dust - mostly Hydrogen, Helium

Properties of Gravitational CollapseProperties of Gravitational CollapseProperties of Gravitational CollapseProperties of Gravitational Collapse

Heating of gas & dust -gravitational energy released -increases temperature of cloud - hotter at center - cooler at edges

Rotation -during collapse, rate of rotation increases -all parts of the cloud rotate in the same direction -causes cloud to flatten into a disk

During Collapse of cloud: -Three temperature regions

Inner Region:Inner Region:Inner Region:Inner Region: -temperature rises above 2000oC -all matter is vaporized -no solid matter, only free atoms

� forms SUNSUNSUNSUN

Midrange Region:Midrange Region:Midrange Region:Midrange Region: -temperature: 0oC to 2000oC -heavier elements can form solids -no light gases or ice (frozen gas)

� forms Terrestrial PlanetsTerrestrial PlanetsTerrestrial PlanetsTerrestrial Planets

Outer Region:Outer Region:Outer Region:Outer Region: -temperature less than 0oC -heavier elements can form solids -light gases and ice are present

� forms Jovian PlanetsJovian PlanetsJovian PlanetsJovian Planets

http://www.pas.rochester.edu/~joel/papers.html

http://www.pas.rochester.edu/~joel/papers.html