Bit of Administration …. ReadingReading –BSNV Chaps. 9 and 15 No Mathieu office hours today...

Bit of Administration ….Bit of Administration ….• ReadingReading

– BSNV Chaps. 9 and 15 BSNV Chaps. 9 and 15

• No Mathieu office hours today (Monday)!No Mathieu office hours today (Monday)!

• Additional observations for Lab 2, through April 5Additional observations for Lab 2, through April 5– Due April 7 in lecture or April 9 at Mathieu officeDue April 7 in lecture or April 9 at Mathieu office

• 12-week exam in two weeks - April 12, 7:15 pm12-week exam in two weeks - April 12, 7:15 pm– Review session, Sunday, April 11, 6:30 pmReview session, Sunday, April 11, 6:30 pm

The Solar SystemThe Solar System

• A Sense of ScaleA Sense of Scale

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Around Earth

Distance to Moon= 0.1=

Around Europe

Distance to North America

The Solar SystemThe Solar System

• A Sense of ScaleA Sense of Scale

The Solar SystemThe Solar System

• A Sense of ScaleA Sense of Scale

The Solar SystemThe Solar System

• InventoryInventory

• SunSun 99.85% by mass99.85% by mass• Planets 0.1 % by massPlanets 0.1 % by mass• Satellites and RingsSatellites and Rings• AsteroidsAsteroids• CometsComets• MeteroidsMeteroids• DustDust• Solar Wind (ionized gas)Solar Wind (ionized gas)

The Solar SystemThe Solar System• Inventory - “Sedna”Inventory - “Sedna”

The Solar SystemThe Solar System

• General Characteristics of General Characteristics of MajorMajor Planets - Dynamical Planets - Dynamical

• Nearly circular orbits (Mercury and Mars most eccentric)Nearly circular orbits (Mercury and Mars most eccentric)

The Solar SystemThe Solar System

• General Characteristics of Major Planets - DynamicalGeneral Characteristics of Major Planets - Dynamical

• Nearly circular orbits (Mercury and Mars most eccentric)Nearly circular orbits (Mercury and Mars most eccentric)• All orbit within 10All orbit within 10oo of Earth’s orbital plane of Earth’s orbital plane

The Solar SystemThe Solar System• General Characteristics of Major Planets - DynamicalGeneral Characteristics of Major Planets - Dynamical

• Nearly circular orbits (Mercury and Mars most eccentric)Nearly circular orbits (Mercury and Mars most eccentric)• All orbit within 10All orbit within 10oo of Earth’s orbital plane of Earth’s orbital plane• All revolve in the same directionAll revolve in the same direction• All rotate in the same direction (except Venus)All rotate in the same direction (except Venus)

The Solar SystemThe Solar System

• General Characteristics of Major Planets - RadiusGeneral Characteristics of Major Planets - Radius

The Solar SystemThe Solar System

• General Characteristics of Major Planets - AgeGeneral Characteristics of Major Planets - Age

• Earth - Oldest rocks 3.9 billion yr (4.5 billion yr inferred)Earth - Oldest rocks 3.9 billion yr (4.5 billion yr inferred)• Moon - 4.5 billion yrMoon - 4.5 billion yr• Meteorites - 4.6 billion yrMeteorites - 4.6 billion yr• Sun - 4.6 billion (theoretical)Sun - 4.6 billion (theoretical)• Universe - 12 billion yrUniverse - 12 billion yr

The Solar SystemThe Solar System• General Characteristics of Major Planets - Physical PropertiesGeneral Characteristics of Major Planets - Physical Properties

TerrestrialTerrestrial

Location InnerLocation InnerSize Small (10Size Small (1044 km) km)Mass 0.1 - 1.0 MMass 0.1 - 1.0 MEarthEarth

Density 5 gm cmDensity 5 gm cm-3-3

Appearance Rock with craters,Appearance Rock with craters, volcanosvolcanosComposition Heavy elementsComposition Heavy elements

7 Giant Satellites7 Giant Satellites

OuterOuterSmall (4000 km)Small (4000 km)0.01 M0.01 MEarthEarth

2-3 gm cm2-3 gm cm-3-3

Rock, ice with craters,Rock, ice with craters,volcanosvolcanosHeavy elements, icesHeavy elements, ices

JovianJovian

OuterOuterLarge (10Large (1055 km) km)15 - 300 M15 - 300 MEarthEarth

1 gm cm1 gm cm-3-3

Gaseous, withGaseous, withrock coresrock coresHydrogen, heliumHydrogen, helium

Mercury Venus Earth Mars

Jupiter Saturn Uranus Nepture

Notes:Notes:

1)1) Densities: Rock = 3 gm cmDensities: Rock = 3 gm cm-3-3, Water = 1 gm cm, Water = 1 gm cm-3-3

2)2) Composition of Sun and Universe by numbers of atoms: Composition of Sun and Universe by numbers of atoms: 94% H, 6% He, 2% all else94% H, 6% He, 2% all else

Io Europa Ganymede Callisto

The Formation of the Solar SystemThe Formation of the Solar System

The Formation of the Solar SystemThe Formation of the Solar System

• Interstellar CloudsInterstellar Clouds

By By MassMass • 73% Molecular Hydrogen73% Molecular Hydrogen• 25%Atomic Helium25%Atomic Helium• 2% Dust (Metals)2% Dust (Metals)

The Taurus clouds are thought to be rather cold, with The Taurus clouds are thought to be rather cold, with temperatures of perhaps 30 K. If you wanted to test this temperatures of perhaps 30 K. If you wanted to test this hypothesis by looking for light hypothesis by looking for light emittedemitted by the Taurus clouds, in by the Taurus clouds, in what wavelength would you want to observe? what wavelength would you want to observe?

A) X-rayA) X-ray B) UltravioletB) Ultraviolet C) OpticalC) Optical D) InfraredD) Infrared E) RadioE) Radio

ConcepTest!ConcepTest!

The Formation of the Solar SystemThe Formation of the Solar System

• Dense Molecular CoresDense Molecular Cores (“Bok Globules”)(“Bok Globules”)

• ≈ ≈ 1 M1 Moo

• ≈ ≈ 50,000 AU50,000 AU• ≈ ≈ 10 10 ooKK

The Formation of the Solar SystemThe Formation of the Solar System

The Formation of the Solar SystemThe Formation of the Solar System

• Protoplanetary DisksProtoplanetary Disks

• ≈ ≈ 0.01 M0.01 Moo

• ≈ ≈ 100 AU100 AU• ≈ ≈ 3000 -> 10 3000 -> 10 ooKK

The Formation of the Solar SystemThe Formation of the Solar System

The Formation of the Solar SystemThe Formation of the Solar System• Condensation SequenceCondensation Sequence

• Condensation Temperature Condensation Temperature Temperature at which Solid Gas Temperature at which Solid Gas

T > 50 T > 50 ooK T > 200 K T > 200 ooK T > 1000 K T > 1000 ooKK

Hydrogen (H)Hydrogen (H)Helium (He)Helium (He)

HH220, Methane (CH0, Methane (CH44))

COCO22, Ammonia (NH, Ammonia (NH33))

Iron (Fe), Silicon (Si)Iron (Fe), Silicon (Si)Metal CompoundsMetal Compounds

Gas Gas Gas

Ice Gas Gas

Rock Rock Gas

The Formation of the Solar SystemThe Formation of the Solar System• Condensation SequenceCondensation Sequence

1000 K 200 KRock

GrainsRock, Ice

GrainsNo Grains

M M JEV

The Formation of the Solar SystemThe Formation of the Solar System

The Formation of the Solar SystemThe Formation of the Solar System• Grain Grain CollisionsCollisions ==> Planetesimals (100 km) ==> Planetesimals (100 km) randomrandom

100 km100 km

The Formation of the Solar SystemThe Formation of the Solar System

• Planetesimal Planetesimal AccretionAccretion ==> Rocky Planets and Jovian Cores ==> Rocky Planets and Jovian Cores gravitygravity

The Formation of the Solar SystemThe Formation of the Solar System

• Gas Gas AccumulationAccumulation ==> H and He onto Jovian Cores ==> H and He onto Jovian Cores gravitygravity

ProtomoonsProtomoons

Most comets have orbits that take them well beyond Jupiter. You Most comets have orbits that take them well beyond Jupiter. You would expect their composition to be: would expect their composition to be:

A) Rocks and heavy elements onlyA) Rocks and heavy elements only B) Rocks and ices onlyB) Rocks and ices only C) Rocks, ices, and hydrogen and heliumC) Rocks, ices, and hydrogen and helium

ConcepTest!ConcepTest!

The Formation of the Solar SystemThe Formation of the Solar System

The Formation of the Solar SystemThe Formation of the Solar System

• Dispersal of Hydrogen and Helium GasDispersal of Hydrogen and Helium Gas• Solar Wind?Solar Wind?• Jets?Jets?