Looking South from Athens Greece Looking South from

Looking South from Athens Greece Looking South from Syene Egypt Scorpius Latitude: 38º N Latitude: 24º N

Earth Shadow during Lunar Eclipse Multiple Exposure Photograph

Cyrene Alexandria Tropic of Cancer Syene

7 14/60º Sunlight Alexandria Syene Earth

North Pole Equator South Pole

North Pole Equator South Pole

North Pole Meridian Equator South Pole

North Pole Meridian Equator South Pole

North Celestial Pole Celestial Sphere Celestial Equator South Celestial Pole

NCP Declination CEq Celestial Meridian SCP

Local Sky Zenith W S N E Horizon

NCP Visible Half of the Sky N Z W E CEq S Below the Horizon SCP

Measuring Latitude Zenith NCP CEq W Latitude S N E Horizon

Z NCP Z W NCP S N E Z NCP Equator North Pole W N S E 40º N Latitude

Zenith Above Horizon for > 12 h NCP Above Horizon for 12 h Above Horizon for < 12 h W N S Never Rises Never Sets E CEq

NCP Ecliptic CEq ~23. 5º Obliquity of the Ecliptic SCP

NCP Summer Solstice c i t p li c E Winter Solstice SCP CEq

NCP Autumnal Equinox Summer Solstice c i t p li c E Winter Solstice Vernal Equinox SCP CEq

Z Summer Solstice NCP Vernal & Autumnal Equinoxes CEq W Winter Solstice N S E

Z Summer Solstice NCP Vernal & Autumnal Equinoxes W Winter Solstice N S E CEq

September June December March

Equinoxes: March 20 & Sept. 22 Northern Spring/Fall Southern Fall/Spring

December 21: Winter Solstice Northern Winter Southern Summer

June 21: Summer Solstice Northern Summer Southern Winter

1 KW/m 2 1 m 2 2 m 2

2000 Dec 21: Winter Solstice 2001 Mar 20: Vernal Equinox Winter Spring Summer Autumn 2001 June 21: Summer Solstice 2001 Sept 22: Autumnal Equinox Summer Autumn Winter Spring

Cepheus Draco Ursa Minor Polaris 2000 AD Thuban 2700 BC

Precession of the Equinoxes

Moon at Perigee Moon at Apogee

Last Quarter Waning Crescent Waning Gibbous Full Moon New Moon Waxing Crescent Waxing Gibbous First Quarter

Moonrise & Moonset at 1 st Quarter Sunrise Noon Moonrise Sunset Midnight Moonset

Moonrise & Moonset at Full Moonrise Sunrise Noon Midnight Sunset Moonrise

Sunrise Noon Moonset Midnight Moonrise Sunset Moonrise & Moonset at Last Quarter

Sidereal vs. Synodic Months T=29. 5 d (Synodic) T=27. 3 d (Sidereal) T=0 d New Moon

Umbra Penumbra Sun Earth

Uneclipsed Moon Sunlight Penumbral Eclipse Total Lunar Eclipse Partial Lunar Eclipse

Total Lunar Eclipse (Note the ruddy scattered sunlight) Partial Lunar Eclipse

Sunlight Umbra Moon Penumbra Earth

NCP Cross-Quarter Days Autumnal Equinox 4 th c i t p cli E Winter Solstice Vernal Equinox 1 st SCP Summer Solstice 3 rd 2 nd CEq

Solar & Sidereal Days T=24 h (Solar day) n o o N Noon Not to Scale T=23 h 56 m 04 s (Sidereal Day) T=0 h

Earth Inferior Conjunction Superior Conjunction

Maximum Eastern Elongation Earth Maximum Western Elongation

Opposition Earth Conjunction

Eastern Quadrature Opposition Earth Western Quadrature Conjunction

Mars Retrograde Motion in 1994/95 1995 Mar 24 1995 Jan 2 1995 July 4 1994 Sept 24

Mars 11/1998 -10/1999 Saturn Jupiter Saturn & Jupiter 4/1999 - 6/2000 Mercury 10 -12/1999 Venus 6 -11/1999

NCP Celestial Sphere Ecliptic Sphere (Daily E-W Motion) (Annual W-E Motion 23. 5º tilt) Planetary Spheres (Retrograde Motions) SCP

First Quarter More Time Last Quarter Less Time Not to Scale

Epicycle Earth Deferent

Equant Center Earth

Ptolemaic System Earth Mercury Venus Sun Mars Jupiter Saturn

Solar System Venus Mercury Sun Mars Jupiter Saturn Earth

Retrograde Motion Earth Mars

Venus Maximum Eastern Elongation DVenus 46º 1 AU

Semimajor Axis F 1 Center F 2

T=0 d T=10 d Equal Areas in Equal Times

Jan 10 Jan 11 Jan 12 Jan 13 Jan 15 Jan 16 Jan 18 Jan 19

Europa Ganymede Callisto Io

6 5 4 4 3 2 1 6 5 4 3 2 1 3 4 3 2 5 6 1 6 Copernican System 1 Ptolemaic System

Falling Apple: Changing Speed (gets faster as it falls) Same Direction (always falls down)

Ball Swung around on a String: Same Speed, (in uniform circular motion) Changing Direction (swinging around the circle)

Donut Swung around on a String Acceleration Force

Equal and Opposite Force from the Table Net Force is Zero, No Net Motion Force = (apple’s mass) (acceleration due to gravity)

d M 2 M 1 2 d M 2 M 1 d/2 M 1 M 2

d M 2 M 1 d M 2 2 M 1 d 2 M 1 2 M 2

Conic Section Curves Circle Ellipse Parabola Hyperbola

Parabola v = v. E Hyperbola v>v. E Ellipse v. C<v<v. E Circle v = v. C v<v. C

Arctic Circle 66. 5º N: 666 km/h Columbus, Ohio 40º N: 1280 km/h Equator 1670 km/h

Towards Sirius 6 hours later

Wavelength ( ) Speed (c) Frequency (f) (# waves/second)

d=1 B=1 d=2 B=1/4 d=3 B=1/9

Doppler Effect in Sound High Pitch (short waves) Low Pitch (long waves)

T=0 s 0 popped 16 unpopped T=35 s 8 popped 8 unpopped Half-Life = 35 sec

Cool Gas Hot Gas Slow Average Speeds Faster Average Speeds

Prisms disperse light into its component colors White Light Spectrum Prism

Continuous Spectrum Continuum Source Emission-line Spectrum Cloud of Hydrogen Gas Absorption-line Spectrum

Hydrogen Helium Oxygen Neon Iron

Lamp emits light at all energies Continuum Source Cloud of Hydrogen Gas Lamp Light Absorbed by Hydrogen Atoms in the Cloud

Continuum n= n=5 n=4 Energy Level Diagram of 1 H n=3 (2 nd excited state) n=2 (1 st excited state) n=1 (Ground State)

6 2 5 2 4 2 n=3 2 n=6 n=5 n=4 n=3 (2 nd excited state) n=2 (1 st excited state) Larger Jump = More Energy = Bluer Wavelength n=1 (Ground State)

2 6 2 5 2 4 n=2 3 n=6 n=5 n=4 n=3 (2 nd excited state) n=2 (1 st excited state) Photons of all other energies (wavelengths) are ignored and pass on by unabsorbed. n=1 (Ground State)

Spectrum of a Fluorescent Light Mercury

Retina Collecting Area Lens

Simple Refracting Telescope Focus Objective Lens Secondary Lens (Eyepiece)

Prime Focus Secondary Mirror Primary Mirror Cassegrain Focus

4. 5 Billion Years Ago 238 U 206 Pb 235 U 207 Pb Today 238 U 235 U 50% left 1. 2% left 206 Pb 207 Pb 1 half-life 6. 3 half-lives

Seismic Station Crust P-waves Lower Mantle Upper Mantle Core P&S waves Earthquake! S waves Surface Waves Seismic Station

Two Faces of the Moon Maria Near Side Impact Basin Cratered Highlands Far Side

Apollo and Luna Landing Sites A 15 A 17 L 24 L 20 A 12 A 14 A 11 A 16 L 16

Pluto Neptune Mars Uranus Saturn Jupiter Earth Venus Mercury

Pluto Ecliptic

Jupiter Interior Molecular Hydrogen Metallic Hydrogen “Ice” Rock

Saturn Interior Molecular Hydrogen Metallic Hydrogen “Ice” Rock

Interiors of Uranus & Neptune Molecular Hydrogen Rocky Cores Slushy “Ice”Mantles Uranus Neptune

Jupiter Saturn Metallic Hydrogen Uranus Neptune Earth

P Star’s spectrum shifts blueward S S Star’s spectrum shifts redward P