Unit 7 Astronomy Name:______________________ Period:____

Astronomy Vocabulary 1.Celestial Objects: 2.An Arc: 3.Apparent daily motion: 4.Constellations: 5.Polaris: 6.Foucault/s Pendulum 7.Coriolis Effect: 8.Summer Solstice: 9.Winter Solstice: 10.Autumnal Equinox: 11.Vernal Equinox: 12. Ellipse 13.Orbit 14.Foci (Focus) 15.Eccentricity 16.Gravity 17.Inertia 18.Perihelion 19. Aphelion

Astronomy Vocabulary 20.Terrestrial 21.Jovian 22.Stars 23.Spectrum 24.Nebula 25.Protostar 26.Neutron Star 27.Black Hole 28.Galaxies 29.Doppler Shift

Focus Questions ___1. How and why do stars move through our sky? ___2. Explain the apparent motion of the Sun through our sky? How does the path of the Sun change throughout the year? ___3. Why do we have seasons? ___4. How does latitude and the angle of the Sun affect daylight hours? ___5. Explain why we see the Moon’s phases?

___6. Explain what happens during a lunar and solar eclipse? ___7. Why do we have tides? ___8. What is the true shape of an orbit and what are the parts of an orbit? What is the equation to measure an orbit’s eccentricity? ___9. Explain what the HR diagram is used for? Explain our Sun’s properties by using the HR diagram. ___10. Describe galaxies and what theory is used to describe the formation of the universe? How can we tell if celestial objects are moving towards or away from us?

A. Celestial Observations 1.The objects in the sky collectively are called ____________________ _____________________ --They include ____________________________________ --They appear to move in the sky ______________________ --The path they appear to take is in the shape of _______________ 2 2.All objects in the night sky appear to travel in a set path around ____________which is located almost directly over the North Pole of Earth.

Many of the stars form specific patterns, or ________________. Some of these never go below the horizon in New York State. Instead, they appear to circle Polaris over the course of a night. This is about a ten hour time exposure of the northern sky. The arcs are the paths of the stars circling the North Star (Polaris) in the center. These stars can be seen year-round in the northern sky although their exact location each night will vary throughout the year. Orion 3 Other stars appear to move throughout the night from east to west. These are trails of stars that are further to the south in our night sky. Their trails appear almost straight. The constellations and the stars that make them up also appear in different locations throughout the year.

All celestial objects appear to move at a rate of 15 degrees per hour. (From horizon to horizon is about 180 degrees.) Why do these objects appear to move at a rate of 15 degrees per hour? _______________________________________________________ We call this motion the_________________________________ 3.Apparent Solar Day: _________________________________ _________________________________________ 5 B.Terrestrial Observations 1.There are two main motions of Earth: a.Revolution: ___________________________________________ ____________________________________________ Evidence: Different constellations appear in our night sky at different times of the year.

b.Rotation: __________________________________________ ____________________ Evidence: (1)Foucault’s Pendulum: _____________________________ 7 (2)Coriolis Effect: ______________________________

2.Apparent Motion of the Sun: It changes with the seasons and latitude due to: ________________________Earth does not lie directly straight up and down, it is tilted _____________ 9

Summer: _______ ______________________________ ___________ but the sun is NEVER directly overhead for us! Because the path of the sun is longest in the summer, days are longest. Summer Solstice: _____________________________ ___________________________________________ Winter: _____________________________________ ___________________________________________ Winter Solstice: ______________________________ ___________________________________________ 10

Spring and Fall: ______________ Vernal Equinox: _____________ Autumnal Equinox: ______________ At the _______________, day and night are 12 hours long everywhere on Earth. Latitude: The closer you are to the poles, the lower the noon time sun and the greater the difference between the winter and summer length of daylight. At the equator, day and night are 12 hours long all year. Important Note: We do not have summer in June because we are closer to the sun. We are actually closest to the sun in December, the beginning of winter. 11

Sun’s apparent path for four different observers on June 21 st. Notice how the path and position of the noontime sun change for each location. Tropics of Cancer and Capricorn: 23.5 o north and south latitude. Mark the furthest north and south travel of the direct rays of the sun. Sun is directly over the Tropic of Cancer on June 21 st and the Tropic of Capricorn on December 21 st. 12

Because the sun is higher in the sky in the summer, the rays of the sun shine down at a more direct angle. The length of shadows cast by a stick are also affected by the height of the sun. In the summer, the sun is high in the sky, so the shadows it casts are ______. Shadows cast in spring and fall are __________. In the winter, the sun is very low in the sky, so the shadow it casts is very ____.

C. Geometry of Orbits I.Terms A. Revolution: __________________________ B. Orbit:_______________________________ 1. Example: __________________________ 2. Ellipse: ___________________________ __________________________________________ 3. Focus (foci): _______________________ 13

4.Eccentricity: ___________________________ _________________________________________ a.Formula: ____________ 5.Period: _________________________________ __________________________________________ 14

II.Force and Energy A. Gravity: __________________________ ________________________________________ B. Inertia: ___________________________ ________________________________________ C. Energy and Orbits 1. At perihelion: ____________________ ________________________________________ 2. At aphelion: _____________________ ________________________________________ 3. This change that occurs during the orbit of Earth is an example of a ______________ ________________________________________ 15

III.Orbits and Johannes Kepler A. Orbital Velocity: _____________________ B. Earth’s Orbit 1. perihelion: ________________________ _________________________________________ 2. aphelion: _________________________ _________________________________________ 16

C.Kepler’s Laws of Planetary Motion -Johannes Kepler, a German astronomer during the late 1500’s to early 1600’s, developed three laws of motion of objects in the sky to help better explain and predict their motions. Before Kepler, most astronomers agreed that planetary orbits were circular. 1. Elliptical Orbits: ______________________ _________________________________________ 2. Equal Areas: _________________________ _________________________________________ 17

_________ _____________________ Note that as the orbiting body gets closer to the object it is orbiting, the pull of gravity becomes stronger. Therefore, its forward speed must also be greater to compensate. 18

3. Harmonic Motion: a. Astronomical Unit: ____________________ _________________________________________ The square of the time of revolution (T 2 ) is proportional to the cube of its mean distance from the Sun (R 3 ) 19

D. Satellite Motions I.The Moon: ____________________________ A. Orbit _____________________________ _________________________________________ 1. Sidereal month: ___________________ _________________________________________ 2. Synodic (lunar) month: _____________ _________________________________________ 20

One synodic month later (29 ½ days) (27 1/3 days) 21

B.Phases: ________________________________ __________________________________________ C Phases change from: ____________ 22 E. As a result, if you look at the moon two consecutive nights, the moon is farther ______ the second night and each night thereafter. Because of the moon orbiting Earth, each day the moon rises over the eastern horizon _______ ___________________.

New Moon New CrescentFirst Quarter New Gibbous Full Moon Old Gibbous Third Quarter Old Crescent

D. Because of the moon orbiting Earth, each day the moon rises over the eastern horizon ______________ ___________. E. As a result, if you look at the moon two consecutive nights, the moon is farther ________ the second night and each night thereafter. Day 1

C.Tides: _________________________________ __________________________________________ 1. High and Low: ________________________ __________________________________________ 2. Normal: ______________________________ __________________________________________ NOTE: Even though the sun is much larger, the moon is much closer so the primary force pulling on the tides is the moon. 23

3.Spring:_________________________________ __________________________________________ 4.Neap: __________________________________ __________________________________________ 24

D.Eclipses: ________________________________ __________________________________________ 1. Shadow Geometry a. umbra: ____________________________ b. penumbra: _________________________ __________________________________________ 25

2.Solar Eclipse: __________________________ ________________________________________ a. total: ______________________________ b. partial: ____________________________ c. annular: ___________________________ _______________________________________ 26

3.Lunar: _________________________________ __________________________________________ a. total: ________________________________ __________________________________________ b. partial: ______________________________ __________________________________________ NOTE: Lunar eclipse does not occur during every full moon because the plane of the moon’s orbit is slightly off from Earth’s. 27

E. The Solar System I.Solar System: __________________________ A. Models 1. Geocentric: _________________________ _________________________________________ epicycle: ___________________________ _________________________________________ Retrograde Motion: ___________________ 28

Geocentric Model of the Solar System Problem:_____________________________ ____________________________________ 29

2.First Heliocentric: _______________________ _________________________________________ Problem: __________________________________ _________________________________________ 3.Revised Heliocentric: _____________________ _________________________________________ 30

B.Objects 1. Sun: __________________________________ ____________________________________________ a. sunspots: ___________________________ ___________________________________________ b. flares/prominences: ___________________ ____________________________________________ 2. Planets: _______________________________ a. Terrestrial: __________________________ ____________________________________________ b. Jovian: _____________________________ ____________________________________________ 3. Asteroids: ______________________________ ____________________________________________ 31

B.Objects (cont.) 4. Meteors: ____________________________ _________________________________________ 5. Comets: _________________________________________ Sun Earth Comet 32

F. The Universe I.Parts of the Universe A. Stars: ______________________________ __________________________________________ 1. Energy: __________________________ _________________________________________ 2. Composition: _____________________ _________________________________________ a. spectrum: _______________________ _________________________________________ b. spectroscope: ____________________ __________________________________________ 33 Star Life Cycle: Stars are like humans. They are born, live and then die.: Nebula: ____ ___________

Protostar: _____________ _____________________ 34 Mature star:___________ ____________ Red Giant:__________ ___________________ _____________

White Dwarf: ______ _________________ Supernova: ______ ________________ 36

The life cycle of stars depends on their mass. Small and medium stars become black dwarves once they die. Larger stars become novae and die as: ____________ The most massive stars become supernovae and die as: ______________________ Neutron Star: ______________________________ _________________________________________ Black Hole: _____________________________ _______________________________________ 37

3.Classifying: _____________________________ __________________________________________ 38

B.Galaxies: _______________________________ __________________________________________ 1. Composition: _________________________ __________________________________________ 2. Size: ________________________________ 3. The Milky Way: ______________________ _________________________________________ 39

These are galaxy clusters and separate galaxies taken by long-range telescope. The area of the sky covered is less than the diameter of the moon. 40

C. Clusters: ____________________________ __________________________________________ II.Distance in the Universe A. The speed of light: ___________________ _________________________________________ B. The Light Year: _____________________ _________________________________________ III.The Expanding Universe A. The Big Bang Theory: ________________ _________________________________________ B. Doppler Shift 1. red shift: __________________________ __________________________________________ 2. blue shift: _________________________ __________________________________________ 41

Since the spectrum for all galaxies show a _______ from Earth, we assume the universe is __________ 42