astronomy - notes

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ASTRONOMY ASTRONOMY The study of The study of stars and space. stars and space.

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Page 1: Astronomy - Notes

ASTRONOMYASTRONOMY

The study of stars The study of stars and space.and space.

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I. Earth’s Place in the I. Earth’s Place in the UniverseUniverse

1.1. Planet Earth – Planet Earth – a a small dense rocky small dense rocky planetplanet

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2. Our Solar System2. Our Solar System

Earth is one of Earth is one of 88 planets that orbit the sun – planets that orbit the sun – an average yellow star.an average yellow star.

3:47

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The PlanetsThe Planets

Orbits of Orbits of the the planets planets and their and their relative relative distancesdistances..

3:41

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3. 3. Milky Way GalaxyMilky Way Galaxy

Our Sun/solar Our Sun/solar system is one system is one of an of an estimated estimated 180 180 billionbillion stars stars making up this making up this spiral galaxyspiral galaxy

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4. Universe4. Universe

Our Milky Way Our Milky Way Galaxy is one of Galaxy is one of billionsbillions of galaxies of galaxies in an expanding in an expanding universeuniverse

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II. Models of the UniverseII. Models of the Universe

A.A. Geocentric Geocentric ModelModel

1.1. About 2000 years About 2000 years ago, the Greek ago, the Greek astronomer, astronomer, Claudius Claudius Ptolemy Ptolemy developed a developed a detailed model of detailed model of the universe based the universe based on the idea of on the idea of revolving spheres.revolving spheres.

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E. Models of the UniverseE. Models of the Universe

2.2. In this model of In this model of the universe, the universe, EarthEarth was at the was at the center, and all center, and all heavenly bodies heavenly bodies moved around moved around EarthEarth in in Perfect Perfect circles.circles.

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3. Ptolemy’s Geocentric model, as 3. Ptolemy’s Geocentric model, as illustrated on the next page, can be illustrated on the next page, can be

summarized as follows:summarized as follows:

a.a. EarthEarth is located in is located in the the centercenter and and does not move.does not move.

b.b. The The starsstars are are located on a located on a transparent sphere transparent sphere that rotates once that rotates once each day from each day from easteast to to westwest around around Earth.Earth.

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c.c. The The SunSun, the , the MoonMoon and each and each planetplanet are are carried by separate carried by separate spheres of different spheres of different sizes.sizes.

d.d. Each planet is located Each planet is located on an on an “epicycle”“epicycle” that that also rotates. This also rotates. This explained explained retrograde retrograde motion.motion.

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Retrograde MotionRetrograde Motion

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d. This model was accepted for almost 1400 years because it d. This model was accepted for almost 1400 years because it explained celestial observations made from Earth and……… explained celestial observations made from Earth and……… it it

seemed obvious.seemed obvious.

However –However –

f.f. The geocentric model does NOT The geocentric model does NOT explain terrestrial (Earth) explain terrestrial (Earth) observations such as:observations such as:

1.1. The movement/rotation of a The movement/rotation of a pendulum’s direction.pendulum’s direction.

2.2. The curvature of the paths of The curvature of the paths of projectiles, winds & ocean currents.projectiles, winds & ocean currents.

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B. Heliocentric ModelB. Heliocentric Model1.1. In the 1500’s, a In the 1500’s, a

new model of the new model of the universe was universe was proposed in a proposed in a book by the book by the Polish astronomer Polish astronomer Nicholas Nicholas Copernicus.Copernicus.

2.2. In this model of In this model of the universe, the the universe, the sunsun was the was the center.center.

2:08

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B. Heliocentric ModelB. Heliocentric Model

Copernicus’ heliocentric model can be Copernicus’ heliocentric model can be summarized as follows:summarized as follows:

1.1. The The SunSun is located in the is located in the centercenter of the system of the system and does NOT move.and does NOT move.

2.2. The The starsstars are located on a stationary/unmoving are located on a stationary/unmoving transparent sphere. The sphere is a great transparent sphere. The sphere is a great distance from the sun.distance from the sun.

3.3. The The planetsplanets, including , including EarthEarth, move in , move in circlescircles around the sun.around the sun.

4.4. The The MoonMoon moves in a circle around moves in a circle around EarthEarth..5.5. EarthEarth rotates on its axis from west toward east rotates on its axis from west toward east

each day.each day.

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However…..However…..

d.d. Copernicus’ Copernicus’ heliocentric model heliocentric model does NOT explain the does NOT explain the apparent cyclic apparent cyclic variations in the size variations in the size of the Sun, and the of the Sun, and the cyclic variation in cyclic variation in orbital speeds of the orbital speeds of the planets. This is planets. This is because in the because in the heliocentric model, heliocentric model, the planets orbit the planets orbit the sun in perfect the sun in perfect circlescircles..

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Brainstorming RulesBrainstorming Rules

1.1. Inspect the questionInspect the question2.2. Develop as many ideas as possible as Develop as many ideas as possible as

quickly as you can.quickly as you can.3.3. Stretch your thinking. Each idea should Stretch your thinking. Each idea should

be new and different (think creatively be new and different (think creatively and divergently), but you can build off of and divergently), but you can build off of other’s ideas.other’s ideas.

4.4. All responses are acceptable. Do not All responses are acceptable. Do not JUDGE someone’s ideas.JUDGE someone’s ideas.

5.5. Work within the time limit (5 minutes).Work within the time limit (5 minutes).

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STEPSSTEPS

1.1. Select a recorderSelect a recorder2.2. Time limit is 5 minutesTime limit is 5 minutes3.3. Recorder should record each idea as stated. Recorder should record each idea as stated.

One idea must come from each participant One idea must come from each participant before proceeding to the next.before proceeding to the next.

4.4. You are encouraged to build on others’ ideas You are encouraged to build on others’ ideas and generate as many possible within the time and generate as many possible within the time frame.frame.

5.5. Examine and group the responses according to Examine and group the responses according to their quality (Great, Good and Just OK).their quality (Great, Good and Just OK).

6.6. Present the BEST idea for solving the problem.Present the BEST idea for solving the problem.

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This animation shows twelve images of the sun, each taken through a telescope on Earth, one month apart. The dates range from August 2000 to July 2001. The dark markings on the sun are sunspots—regions where the surface is slightly cooler than the surrounding area. Notice how the size of the sun appears to change in a regular pattern.

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SO..The question is:SO..The question is:

Why does the size of the Why does the size of the sun appear to change?sun appear to change?

AnswerAnswer: All stars change size over their lifetimes, : All stars change size over their lifetimes, but the sun is currently very stable. Evidence but the sun is currently very stable. Evidence indicates the sun has a constant diameter of about indicates the sun has a constant diameter of about 1.4 million kilometers. The only reasonable 1.4 million kilometers. The only reasonable explanation for the change in the sun's apparent size explanation for the change in the sun's apparent size is that Earth's distance from the sun changes in a is that Earth's distance from the sun changes in a regular pattern.regular pattern.

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C. Kepler’s Heliocentric C. Kepler’s Heliocentric ModelModel

1.1. In 1609, In 1609, Johannes Johannes KeplerKepler published a book published a book which included his first which included his first 2 “Laws of Planetary 2 “Laws of Planetary Motion”. These laws Motion”. These laws explain why the explain why the apparent size of the sun apparent size of the sun changed, and why the changed, and why the speed of a planet speed of a planet changes as it orbits the changes as it orbits the Sun.Sun.

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This is because…..This is because…..

The orbits of the The orbits of the planets were planets were “elliptical” and not “elliptical” and not circular.circular.

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a. Kepler’s First Lawa. Kepler’s First Law

The orbit of each The orbit of each planet is an planet is an ellipseellipse with the with the sunsun at at one focus and an one focus and an imaginary point imaginary point in spacein space at the at the other focus.other focus.

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An Ellipse – An Ellipse – draw the parts in your notesdraw the parts in your notes

An ellipse looks like an oval, or squashed circle. An ellipse looks like an oval, or squashed circle.

The longest line drawn from one end of the ellipse (through The longest line drawn from one end of the ellipse (through the center) to the other side is called the the center) to the other side is called the major axismajor axis. .

For a circle, the two foci lie on top of each other.For a circle, the two foci lie on top of each other.

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√√ EccentricityEccentricity Eccentricity (e) = the “out of Eccentricity (e) = the “out of

roundness” shape of the ellipse roundness” shape of the ellipse given by the ratio of the given by the ratio of the distance between the two foci distance between the two foci and the length of the major and the length of the major axis.axis.

e =e = distance between focidistance between foci

Length of Major Axis Length of Major Axis

The eccentricity of a circular orbit The eccentricity of a circular orbit is is zerozero, and can range from , and can range from zero to less than one for an zero to less than one for an ellipse. ellipse.

Reference Table page 1

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2. Eccentricity2. Eccentricityd.d. Relationship: As the distance between the focal Relationship: As the distance between the focal

points increase, the shape of the ellipse points increase, the shape of the ellipse becomes more oval (Circle = 0)becomes more oval (Circle = 0)

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B. Kepler’s Second LawB. Kepler’s Second Law describes the fact that describes the fact that a a

planet moves fastest in its planet moves fastest in its orbit when it is nearest the orbit when it is nearest the Sun.Sun. If you imagine a line If you imagine a line connecting the planet and the connecting the planet and the Sun, the line sweeps out Sun, the line sweeps out equal equal areas in equal timesareas in equal times..

Area A = Area B = Area CArea A = Area B = Area C

Maximum speed

Minimum speed

Decreasing speed

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B. Kepler’s Second LawB. Kepler’s Second Law

1.1. Perihelion = point in orbit nearest Perihelion = point in orbit nearest to sunto sun

2.2. Aphelion = point in orbit furthest Aphelion = point in orbit furthest from sunfrom sun

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C. Kepler’s Third LawC. Kepler’s Third Law

The further a The further a particular planet is particular planet is from the sun, the from the sun, the longer it’s period longer it’s period (time) of revolution(time) of revolution..

1. Farther planets 1. Farther planets have have longerlonger orbital orbital pathspaths

2. Farther planets 2. Farther planets have have slowerslower orbital orbital pathspaths

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Table on Page 15Table on Page 15PlanetPlanet DistanceDistance

(millions of miles)(millions of miles)SpeedSpeed mile/sec.mile/sec.

Period of Period of RevolutionRevolution

MercuryMercury 3636 3030 88 88 daysdays

VenusVenus 6767 2222 224 224 daysdays

EarthEarth 9393 1919 365.25 365.25 daysdays

MarsMars 142142 1515 687 687 daysdays

JupiterJupiter 484484 88 11.6 11.6 yearsyears

SaturnSaturn 887887 66 29.46 29.46 yearsyears

UranusUranus 17841784 44 84.01 84.01 yearsyears

NeptuneNeptune 27952795 3.43.4 164 164 yearsyears

Pluto *Pluto * 36753675 33 247 247 yearsyears

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D. Sir Isaac NewtonD. Sir Isaac Newton

1.1. Newton’s Laws of Newton’s Laws of GravityGravity

First LawFirst Lawa)a) All objects with All objects with

mass will be mass will be acted on by acted on by gravitygravity and will pull and will pull all other objects all other objects with a certain with a certain gravitational force.gravitational force.

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Newton’s Laws of GravityNewton’s Laws of Gravityb)b) Newton’s Second Law Newton’s Second Law

The mass of an object The mass of an object will determine the will determine the amount of amount of gravitational forcegravitational force that object possesses. that object possesses. The The greatergreater the the mass, the mass, the greatergreater the the gravitational force.gravitational force.

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Newton’s Laws of GravityNewton’s Laws of Gravity

c)c) Third LawThird LawThe gravitational The gravitational

force between 2 force between 2 objects changes as objects changes as the distance the distance between them between them change. As the change. As the distance distance increasesincreases, , gravitational pull gravitational pull will will decreasedecrease..

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2. Gravity and Inertia2. Gravity and Inertia

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a. Newton’s Law of Inertia a. Newton’s Law of Inertia States that States that an objects motion will an objects motion will

not change unless that object is not change unless that object is acted on by an outside forceacted on by an outside force..

Inertia

Gravity

Stable Orbit

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B. Gravity and InertiaB. Gravity and Inertia

Inertia – Inertia – causes causes a planet to a planet to move in a move in a straight linestraight line..

Gravity – Gravity – pulls a pulls a planet toward planet toward the sun.the sun.

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History Summary History Summary (16 m)(16 m)

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RotationRotation

The spinning of a The spinning of a celestial body celestial body (Earth) on an (Earth) on an imaginary axisimaginary axis

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III. RotationIII. Rotation

A. Earth’s Direction of Rotation:A. Earth’s Direction of Rotation:WESTWEST to to EASTEAST

2. Angular Rate of Rotation:2. Angular Rate of Rotation:

THINK – one complete rotationTHINK – one complete rotation

a. a. 360360 degreesdegrees

b. b. 2424 hourshours

RateRate = 360 = 36000/24 hours = /24 hours = 151500/hour/hour

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B. Effects of Earth’s B. Effects of Earth’s RotationRotation

1.1. Day and NightDay and Night

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B. Effects of Earth’s B. Effects of Earth’s RotationRotation

2.2. Apparent daily Apparent daily motion motion of the sunof the sun

a. Earth rotates from a. Earth rotates from WESTWEST to to EASTEAST

b. Sun “appears” to b. Sun “appears” to move in an arc from move in an arc from EASTEAST to to WESTWEST

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B. Effects of Earth’s B. Effects of Earth’s RotationRotation

3.3. Apparent daily Apparent daily motion of the motion of the starsstars

Appear to rise in the Appear to rise in the easteast and set in and set in the the westwest..

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Looking EastLooking West

Looking North Looking South

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B. Effects of Earth’s B. Effects of Earth’s RotationRotation

b.b. The apparent The apparent daily motion of daily motion of celestial celestial objects (like objects (like stars) changes stars) changes when the when the observer’s observer’s latitudelatitude on on Earth changes.Earth changes.

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B. Effects of Earth’s B. Effects of Earth’s RotationRotation

C.C. The apparent daily motion of the Big The apparent daily motion of the Big Dipper, a Dipper, a circumpolarcircumpolar constellation. constellation.

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Location of ObserverLocation of Observer New York StateNew York State

DateDate Mid OctoberMid October

Position of the big Position of the big dipperdipper

9:00 pm9:00 pm 11

3:00 am3:00 am 22

9:00 am9:00 am 33

3:00 pm3:00 pm 44

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B. Effects of Earth’s B. Effects of Earth’s RotationRotation

d.d. Star TrailsStar Trails – a – a time-exposed time-exposed photographic photographic image that shows image that shows the apparent the apparent motion of stars; it motion of stars; it appears as a appears as a blurry line across blurry line across the film.the film.

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Star trail photographs looking Star trail photographs looking north, south, east and westnorth, south, east and west

A. North

D. EastC. West

B. South

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Celestial Poles – video clipCelestial Poles – video clip

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IV. RevolutionIV. Revolution The orbiting of one celestial body around another The orbiting of one celestial body around another

celestial body.celestial body.A. Earth’s Angular Rate of RevolutionA. Earth’s Angular Rate of Revolution

1. 360 degrees1. 360 degrees2. 365 days2. 365 days3. Rate = 3603. Rate = 36000/365 days ~ = /365 days ~ = 1100/day/day

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B. Effects of Earth’s B. Effects of Earth’s RevolutionRevolution

1.1. Nighttime Nighttime constellations constellations change in a yearly change in a yearly cycle.cycle.

2.2. ConstellationConstellation – – groups of stars that groups of stars that form patterns of form patterns of imaginary things imaginary things such as animals, such as animals, legendary heroes, legendary heroes, and mythological and mythological godsgods

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3. 3. ZodiacZodiac – a band of 12 constellations that forms a – a band of 12 constellations that forms a background for the Sun as seen from the revolving background for the Sun as seen from the revolving

Earth.Earth.

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Continued: Effects of Earth’s RevolutionContinued: Effects of Earth’s Revolution

2.2. Position of the Big Position of the Big Dipper (and other Dipper (and other circumpolar circumpolar constellations) constellations) changes position in a changes position in a yearly cycle.yearly cycle.

1

2

3

4

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Location of ObserverLocation of Observer NYSNYS

Time of DayTime of Day 12:00 Midnight12:00 Midnight

Position of the Big DipperPosition of the Big Dipper

FallFall 11

WinterWinter 22

SpringSpring 33

SummerSummer 44

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3. 3. SeasonsSeasons – a yearly cycle – a yearly cycle

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5. Seasons of the Year5. Seasons of the Year

A.A. Causes:Causes:

1.1. Earth revolves around the sunEarth revolves around the sun

2.2. Earth is tilted/inclined on axis 23 1/2Earth is tilted/inclined on axis 23 1/2oo

3.3. Earth’s axis always points in the same Earth’s axis always points in the same direction.direction.

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B. Earth’s axis is tilted B. Earth’s axis is tilted 23.523.500 relative to the relative to the plane of it’s orbit.plane of it’s orbit.

Draw and label Draw and label your diagram your diagram according to the according to the diagram at the diagram at the right. Be sure right. Be sure to name the to name the equator, the equator, the Tropic of Cancer Tropic of Cancer and Capricorn and Capricorn and note where and note where we live.we live.

NYS 43 o

Tropic of CancerEquator

Tropic of Capricorn

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C. Earth revolves around the Sun in a yearly cycle of 365 ¼ C. Earth revolves around the Sun in a yearly cycle of 365 ¼ days.days.

D. As Earth revolves, D. As Earth revolves, its axis always points in the same its axis always points in the same directiondirection (parallelism of axis)(parallelism of axis)

December 21

March 21

June 21

Sept. 20

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E. The apparent path of the sun changes with the E. The apparent path of the sun changes with the seasonsseasons and with and with latitudelatitude..

1.1. N.Y.S. 43N.Y.S. 43oo North Latitude North Latitude

24o

47o

71o

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2. Equator 02. Equator 0oo Latitude Latitude

67o 67o

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F. Length of Daylight (duration of daylight) – changes with F. Length of Daylight (duration of daylight) – changes with seasonsseasons and with and with latitudelatitude..

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G. Angle of Insolation G. Angle of Insolation (Sunlight) and Heating of (Sunlight) and Heating of

Earth’s SurfaceEarth’s Surface

High Angle

High Intensity

Low Angle

Low Intensity

1.

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G. Angle of Insolation G. Angle of Insolation (Sunlight) and Heating of (Sunlight) and Heating of

Earth’s SurfaceEarth’s Surface1.1. The intensity (strength) of insolation The intensity (strength) of insolation

is greatest when is greatest when sunlight sunlight (insolation) is perpendicular to the (insolation) is perpendicular to the surface – striking at 90surface – striking at 90oo because because the sunlight is concentrated in the the sunlight is concentrated in the smallest possible area.smallest possible area.

2.2. As the angle of insolation As the angle of insolation increasesincreases, the intensity of , the intensity of insolation insolation increasesincreases..

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H. Factors affecting InsolationH. Factors affecting Insolation1.1. Shape of the Earth (spherical)Shape of the Earth (spherical)

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2. As latitude increases, the angle of insolation 2. As latitude increases, the angle of insolation decreasesdecreases, and the intensity of insolation , and the intensity of insolation

decreasesdecreases..a.a.

b.b.

Angle

of

inso

lati

on

0o Latitude 90o

Inte

nsi

ty o

f in

sola

tion

0o Latitude 90o

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3. Season of the Year3. Season of the Year

a.a. As Earth travels along its orbital path As Earth travels along its orbital path around the sun, the angle of insolation around the sun, the angle of insolation at a given latitude changes with the at a given latitude changes with the seasons. This depends on how far a seasons. This depends on how far a given latitude is from the direct rays of given latitude is from the direct rays of the sun. The direct rays migrate the sun. The direct rays migrate between the between the Tropic of Cancer Tropic of Cancer (north)(north) and the and the Tropic of Capricorn Tropic of Capricorn (south).(south).

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b. Key:b. Key: Direct Ray of Sunlight (Perpendicular to Direct Ray of Sunlight (Perpendicular to Earth’s Surface; 90Earth’s Surface; 90oo))

Ray of Sunlight (striking NYS at an Ray of Sunlight (striking NYS at an angle less than 90angle less than 90oo))

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C. Maximum angle of insolation at 12 C. Maximum angle of insolation at 12 noon for mid N.Y.S. (Lat. 43noon for mid N.Y.S. (Lat. 43oo N) N)

1. Dec. 21 2. Mar/Sep. 21 3. June 21

24.5 48 71.5

Low angle

Low intensity

Medium angle

Medium intensity

High angle

High intensity

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4. 4. Time of DayTime of Day

a.a. The angle The angle of of insolation insolation changes in changes in the course the course of one day. of one day. Maximum Maximum intensity intensity occurs at occurs at NoonNoon..

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b. Angle of Insolation vs. b. Angle of Insolation vs. TimeTime

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d. Looking Southd. Looking South

The shadow of a vertical pole indicates how the angle of The shadow of a vertical pole indicates how the angle of insolation changes during the day. The higher/greater the insolation changes during the day. The higher/greater the angle of insolation, the angle of insolation, the shortershorter the shadow, and the the shadow, and the greatergreater the intensity of insolation. the intensity of insolation.

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V. Celestial ObservationsV. Celestial Observations

A.A. Celestial ObjectCelestial Object = The objects = The objects observed in the sky during the day observed in the sky during the day or night (outside of Earth’s or night (outside of Earth’s atmosphere)atmosphere)

Examples: Planets, Sun, Moon, Examples: Planets, Sun, Moon, stars, comets, asteroidsstars, comets, asteroids

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V. Celestial ObservationsV. Celestial Observations

B.B. Celestial Celestial SphereSphere = = Model of the Model of the skysky

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Celestial SphereCelestial Sphere

C.C. ZenithZenith – highest point in the sky directly above – highest point in the sky directly above the observer’s head.the observer’s head.

D.D. HorizonHorizon – imaginary boundary between the sky – imaginary boundary between the sky and groundand ground

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E. Location on the Celestial E. Location on the Celestial Sphere – THE HORIZON Sphere – THE HORIZON

SYSTEMSYSTEM1.1. AltitudeAltitude = =

angular distance angular distance above the above the horizon. From 0horizon. From 0oo on the horizon to on the horizon to 9090oo at zenith. at zenith.

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Location on the Celestial Location on the Celestial Sphere – THE HORIZON Sphere – THE HORIZON

SYSTEMSYSTEM2.2. AzimuthAzimuth = Angular = Angular

distance along the distance along the horizon from N horizon from N (0o), clockwise (0o), clockwise

Mark the rose Mark the rose compass on your compass on your notes as you see in notes as you see in the picture on the the picture on the right!right!

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3. Model problems3. Model problems

By careful estimation, By careful estimation, determine the azimuth determine the azimuth (Az) and the altitude (Az) and the altitude (h) for the star ( ) (h) for the star ( ) illustrated in each illustrated in each celestial sphere celestial sphere diagram. diagram.

Example: Example: Common termsCommon terms AzAz hh

EE 1/31/3DegreesDegrees 909000 3030oo

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Our Sun – Future Our Sun – Future

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VI The MoonVI The MoonA.A. The moon is a The moon is a natural satellite of Earthnatural satellite of Earth. .

1. 1. LunaLuna – Latin for moon – Latin for moon

2. 2. DianaDiana – Roman goddess of the moon – Roman goddess of the moon

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B. Physical Properties of the B. Physical Properties of the MoonMoon

1.1. SizeSizea.a. Diameter: 2160 Diameter: 2160

milesmilesb.b. Compared to EarthCompared to Earth

Diameter of Diameter of MoonMoon = = 21602160 = = 11

Earth 8000 Earth 8000 44

2.2. GravityGravitya.a. 1/6 1/6 the gravity of the gravity of

EarthEarthb.b. Smaller – less massSmaller – less mass

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2. Atmosphere2. Atmosphere

a.a. The Moon hasThe Moon has No No atmosphere, so atmosphere, so radiation from sun radiation from sun strongstrong

Sunburn in secondsSunburn in seconds

b.b. Gravity too weak soGravity too weak so gases escape into gases escape into space.space.

c.c. Frozen water may exist at Frozen water may exist at the Moon’s the Moon’s polar polar regions,regions, but none in but none in liquid formliquid form

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3. Temperatures3. Temperatures

a.a. 240240ooF F on the lighted on the lighted sideside

b.b. - 240- 240ooFF on the far on the far sideside

c.c. These large These large temperature temperature extremes or extremes or differences exist differences exist because because the moon the moon does not have an does not have an atmosphere to atmosphere to transfer heat.transfer heat.

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4. Lunar Topography – surface 4. Lunar Topography – surface features of the moonfeatures of the moon

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““The Dark Side of The The Dark Side of The Moon”Moon”

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a. a. CratersCraters – bowl-shaped depressions – bowl-shaped depressions formed primarily as a result of impact formed primarily as a result of impact

of meteors.of meteors.i.i. Examples: Copernicus, Kepler, Tycho, Examples: Copernicus, Kepler, Tycho,

PtolemaeusPtolemaeusii.ii. Most cratering occurred during heavy bombardment period Most cratering occurred during heavy bombardment period

which gave Earth its early CO2 atmosphere ~4billion years agowhich gave Earth its early CO2 atmosphere ~4billion years ago

Some of these craters filled with lava which is now smooth and Some of these craters filled with lava which is now smooth and glassyglassy

i.i. There are many more craters on the There are many more craters on the moon than on Earth because… moon than on Earth because… the the moon does not have an atmosphere to 1. moon does not have an atmosphere to 1. burn up incoming meteors and 2. no burn up incoming meteors and 2. no weathering and erosion!weathering and erosion!

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b. Mariab. Maria The smooth, glassy regions, which are The smooth, glassy regions, which are

generally craters filled in by lava, are generally craters filled in by lava, are called called mariamaria

c. c. raysrays – appear as – appear as “bright streaks”“bright streaks” that that radiate from certain craters. radiate from certain craters.

d.d. The rough regions surrounding them are The rough regions surrounding them are calledcalled “ “lunar highlandslunar highlands”. ”. Consist ofConsist of craterscraters andand mountainsmountains

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MOON FUN FACTSMOON FUN FACTS The moon is actually moving away from The moon is actually moving away from

earth at a rate of 1.5 inches per year.earth at a rate of 1.5 inches per year.

Only about 59 percent of the moon's Only about 59 percent of the moon's surface is visible to us here on earth.surface is visible to us here on earth.

The moon is not round, but egg shaped The moon is not round, but egg shaped with the large end pointed towards with the large end pointed towards earth.earth.

The earth rotates about 1000 mph. By The earth rotates about 1000 mph. By comparison, the moon rotates about 10 comparison, the moon rotates about 10 mph.mph.

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5. The Moon’s Revolution5. The Moon’s Revolutiona.a. Period of RevolutionPeriod of Revolution

b.b. 1 month1 month OR ORc.c. 29.529.5 days daysd.d. The moon revolves The moon revolves

around Earth in an around Earth in an ellipticalelliptical orbit, and orbit, and Earth is at one Earth is at one focusfocus..

e.e. This causes the This causes the moon’s apparent moon’s apparent diameter/sizediameter/size to to change in a change in a cycliccyclic manner.manner.

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6. Phases of the Moon6. Phases of the Moon

a.a. Caused by Caused by the moon’s revolution the moon’s revolution around Earth.around Earth.

b.b. Our Earth view of the changing Our Earth view of the changing illuminated part of the moon’s illuminated part of the moon’s surface that face’s Earth.surface that face’s Earth.

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7. Moon Rotation7. Moon Rotation

3.3. Does that mean Does that mean the moon doesn't the moon doesn't rotate? No, it rotate? No, it doesdoes rotate-- rotate--one one rotation for rotation for each revolution each revolution around Earth!around Earth!

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Eclipses Eclipses

Lunar EclipseLunar Eclipse Solar EclipseSolar Eclipse Solar Eclipse – different viewSolar Eclipse – different view

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10. Tides10. Tidesa.a. Tides are the Tides are the

periodic rising and periodic rising and falling of the falling of the oceansoceans..

b.b. Caused by the Caused by the moon’s moon’s gravitational pull gravitational pull on Earthon Earth

c.c. Affected by Earth’s Affected by Earth’s rotation and rotation and distance.distance.

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d.d. The period from high tide to high tide is The period from high tide to high tide is normally about normally about 1212 hours and 25 minutes. hours and 25 minutes.

e.e. Tides are a Tides are a cycliccyclic change. change.

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VII. Earth’s Place in the VII. Earth’s Place in the UniverseUniverse

A.A. Light YearLight Year1.1. The distance light travels in one (1) The distance light travels in one (1)

year.year.

2.2. 6,000,000,000,000 miles (6.0 x 106,000,000,000,000 miles (6.0 x 101212))

3.3. The speed of light is 186,000 mi/sec.The speed of light is 186,000 mi/sec.

4.4. a. We see all night stars as they WERE a. We see all night stars as they WERE when the light when the light left that starleft that star..

b.b. When we look at distant stars and galaxies, When we look at distant stars and galaxies, we look back in we look back in timetime..

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Scale Model DistanceScale Model Distance

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B. GalaxiesB. Galaxies

1.1. Billions of stars Billions of stars held together by held together by gravity.gravity.

2.2. Shape of Shape of galaxies:galaxies:

a. a. SpiralSpiral

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Side View of Spiral GalaxySide View of Spiral Galaxy

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b. b. EllipticalElliptical

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c. c. Irregular GalaxyIrregular Galaxy

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D. The Milky Way GalaxyD. The Milky Way Galaxy

1.1. Our sun is only one of the estimated Our sun is only one of the estimated 180 Billion180 Billion stars that make-up the stars that make-up the Milky Way Galaxy.Milky Way Galaxy.

2.2. The Milky Way is a The Milky Way is a SpiralSpiral galaxy. galaxy.

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a. Top Viewa. Top View

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b. Side Viewb. Side View

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Life Cycle of Stars – Life Cycle of Stars – H.R.DiagramH.R.Diagram

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VIII. Evolution of the VIII. Evolution of the UniverseUniverse

A.A. Electromagnetic EnergyElectromagnetic Energy1.1. The The sunsun is the major energy source for weather changes is the major energy source for weather changes

in the atmosphere and many of the changes occurring at in the atmosphere and many of the changes occurring at Earth’s surface.Earth’s surface.

2.2. Energy from the sun comes in Energy from the sun comes in many different many different wavelengths.wavelengths.

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Electromagnetic Spectrum Electromagnetic Spectrum (4.5 min)(4.5 min)

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1.1. RadioRadio

2.2. TV/Radar/microTV/Radar/micro

3.3. InfraredInfrared

4.4. Visible/White lightVisible/White light

5.5. UV (ultraviolet)UV (ultraviolet)

6.6. X-RaysX-Rays

7.7. GammaGamma

8.8. CosmicCosmic

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Dark line SpectrumDark line Spectrum

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B. Doppler Effect – B. Doppler Effect – apparent change in apparent change in

the wavelength of light (or sound) that occurs when an object the wavelength of light (or sound) that occurs when an object is moving toward or away from the observeris moving toward or away from the observer..

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2. Red Shift – Blue Shift2. Red Shift – Blue Shift

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3.3. The amount of “red shift” is a result The amount of “red shift” is a result of the of the speedspeed at which the galaxy is at which the galaxy is movingmoving..

4.4. Conclusion: As the distance from Conclusion: As the distance from Earth Earth increasesincreases, the amount of red , the amount of red shift of a galaxy increases; this shift of a galaxy increases; this indicates that indicates that the farther a galaxy, the farther a galaxy, the faster it is movingthe faster it is moving..

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C. The Big Bang TheoryC. The Big Bang Theory

a.a. In the late 1920’s, Edwin Hubble In the late 1920’s, Edwin Hubble discovered that All galaxies were discovered that All galaxies were “red-shifted” when viewed from “red-shifted” when viewed from Earth. This meant that all galaxies Earth. This meant that all galaxies were were moving away from Earth and moving away from Earth and each othereach other, and thus, the universe , and thus, the universe must be must be expandingexpanding..

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Big Bang Video ClipBig Bang Video Clip

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D. Evolution of the UniverseD. Evolution of the Universe

Cosmic Evolution

Big Bang

Origin of Matter

Formation of Milky WayFormation of Earth

Present