AstronomyAstronomy

Chapter 22-25Chapter 22-25

Warm Up: Sept 7

http://www.youtube.com/watch?v=jRXQsQKGqIU – creepy twinkle

http://www.youtube.com/watch?v=yCjJyiqpAuU –cute twinkle

Compare and contrast each version using a Venn Diagram

Which one do you like more? Why?Which one best describes human curiosity

towards outer space? WHY?

22

Time Line Time Line Create a time to include each of the following Create a time to include each of the following

people (include their discovery).people (include their discovery). AristotleAristotle Eratosthenes Eratosthenes Hipparchus Hipparchus Aristarchus Aristarchus Claudius PtolemyClaudius Ptolemy Nicolaus Copernicus Nicolaus Copernicus Tycho BraheTycho Brahe Johannes KeplerJohannes Kepler Galileo Galilei Galileo Galilei Sir Isaac Newton Sir Isaac Newton

What is the Golden Age of What is the Golden Age of Astronomy?Astronomy?

The shift away from The shift away from the idea of a the idea of a Geocentric Universe.Geocentric Universe.

What is Modern Astronomy?What is Modern Astronomy? Nicolaus Copernicus Nicolaus Copernicus

(1473-1543)(1473-1543) Earth is just a planetEarth is just a planet Universe is sun centeredUniverse is sun centered

Mercury, Venus, Earth, Mars, Mercury, Venus, Earth, Mars, Jupiter, and SaturnJupiter, and Saturn

Circular orbits around sunCircular orbits around sun

Tycho Brahe (1546-1601)Tycho Brahe (1546-1601) Used pointers to estimate Used pointers to estimate

distancedistance Pointers think big Pointers think big

protractorprotractor Mentor KeplerMentor Kepler

Who was Johannes Kepler Who was Johannes Kepler (1571-1630)?(1571-1630)?

Brahe’s observations of Mars Brahe’s observations of Mars Noticed that the orbit was not Circular Noticed that the orbit was not Circular Kepler used his Q&A’s to form 3 Laws of Kepler used his Q&A’s to form 3 Laws of

Planetary MotionPlanetary Motion11stst Law Law

Ellipse (Oval)Ellipse (Oval)2 foci2 foci

StarStar

Laws of Planetary MotionLaws of Planetary Motion

22ndnd Law Law Sun sweeps over Sun sweeps over

equal areas in the equal areas in the same amount of time.same amount of time.

Close to sun fasterClose to sun faster Away from sun slowerAway from sun slower

33rdrd Law Law Orbital Period (time) of Orbital Period (time) of

planet is proportional planet is proportional to distance from the to distance from the sun (Psun (P22=d=d33), ), expressed in AU units expressed in AU units (1AU = 1.5Million Km)(1AU = 1.5Million Km)

Who is Galileo Galilei?(1564-Who is Galileo Galilei?(1564-1642)1642)TelescopeTelescope

Behavior of moving objectsBehavior of moving objectsObservation supported Copernicus’s view of the Observation supported Copernicus’s view of the

universeuniverseMoons of Jupiter (4) = Earth is not the center of all Moons of Jupiter (4) = Earth is not the center of all

universal motionuniversal motionPlanets are circular disc = must be Earth-likePlanets are circular disc = must be Earth-likeVenus has phases like the moon = orbits light source Venus has phases like the moon = orbits light source

(sun)(sun)Moon’s surface not smooth = validated others who Moon’s surface not smooth = validated others who

named areas based on features (Sea of Tranquility)named areas based on features (Sea of Tranquility)Sun has dark regions = tracked movement est. Sun has dark regions = tracked movement est.

rotation period of sun under 1 monthrotation period of sun under 1 month

What is the Law of Universal What is the Law of Universal Gravitation?Gravitation?

Sir Isaac Newton (1642-1727)Sir Isaac Newton (1642-1727)⊗⊗ Kepler “some force pushes the planets along their Kepler “some force pushes the planets along their

orbits” orbits”

Galileo “no force is required to keep an object in Galileo “no force is required to keep an object in motion” motion”

InertiaInertia

Every body attracts directly proportional to Every body attracts directly proportional to mass & inversely proportion to distancemass & inversely proportion to distance22 b/w b/w the bodiesthe bodies

Revised Kepler’s 3Revised Kepler’s 3rdrd law (mass) law (mass)

What are Earth Motions?What are Earth Motions?

RotationRotationSpinning on axis (day/night)Spinning on axis (day/night)

Solar day Solar day noon to noonnoon to noon

Sidereal day Sidereal day Based on a distant star Based on a distant star

23hr 56 min23hr 56 min Distance to the stars change by tiny increments Distance to the stars change by tiny increments Sun changes by 1° a daySun changes by 1° a day

Earth Motions Cont.Earth Motions Cont.

RevolutionRevolutionMoving around another bodyMoving around another body

Distance of the sun to the Earth @150 million kmDistance of the sun to the Earth @150 million kmElliptical OrbitElliptical Orbit

Perihelion @ January 3Perihelion @ January 3 147 million km147 million km

Aphelion @July 4Aphelion @July 4 152 million km152 million km

Earth Motions Cont.Earth Motions Cont.

PrecessionPrecession Change in tilt of axisChange in tilt of axis

23.523.5 always the same always the same Slow @ 26 000 yearsSlow @ 26 000 years

Changes North StarChanges North Star Polaris to VegaPolaris to Vega

NutationNutation Wobbling around the axisWobbling around the axis Caused but the moon’s pullCaused but the moon’s pull Slight seasonal change.Slight seasonal change.

Remember: Galaxies on the move!Remember: Galaxies on the move!

What are Axis & Seasons?What are Axis & Seasons?

Why do different season exist?

Axis & Seasons cont.Axis & Seasons cont.

Moon (Satellite) MotionsMoon (Satellite) Motions

Revolution = 1month (29 ½ days)Revolution = 1month (29 ½ days)Ave. distance = 384 401Km (6%)Ave. distance = 384 401Km (6%)

Perigee = closest to EarthPerigee = closest to EarthApogee = farthestApogee = farthest

Phases of the MoonPhases of the MoonWaxingWaxingWaningWaning

How do Eclipses work?How do Eclipses work?

What is Barycenter?What is Barycenter?

The center of mass is the balance point The center of mass is the balance point between two orbiting bodies, like a between two orbiting bodies, like a seesaw.seesaw.

The SunThe Sun

Average StarAverage Star Some Stats:Some Stats:

Diameter = 109 Diameter = 109 Earth diametersEarth diameters

Volume = 1.25 Volume = 1.25 million times Earth’smillion times Earth’s

Mass = 332,000 Mass = 332,000 times Earth’stimes Earth’s

Density = 1/4Density = 1/4thth of of solid Earth solid Earth

Sun StructureSun Structure

StructureStructure the Solar Interiorthe Solar Interior PhotospherePhotosphere 2 Atmospheric Layers2 Atmospheric Layers

ChromosphereChromosphere Prominences Prominences

CoronaCorona Solar WindsSolar Winds

Solar Flares & SunspotsSolar Flares & Sunspots

Solar FlaresSolar FlaresAuroras Auroras

SunspotsSunspots11 year cycle11 year cycleLast days to weeksLast days to weeks

The Solar interiorThe Solar interior

Nuclear FusionNuclear Fusion E=mcE=mc22

It takes very little It takes very little hydrogen to make a hydrogen to make a lot of energy.lot of energy.

Most of the hydrogen Most of the hydrogen is not converted to is not converted to energy.energy.

Other StuffOther Stuff

Scientific Methods Quiz RedoScientific Methods Quiz Redo A problem is a question to be answered!!!!!A problem is a question to be answered!!!!! Answer the QUESTION!!!!!!!!!!!!!!!!Answer the QUESTION!!!!!!!!!!!!!!!! Do not for get the problem/hypothesis relationship!!!!!Do not for get the problem/hypothesis relationship!!!!!

Example Problem:Example Problem:

Does the Does the presence of grain-eaterspresence of grain-eaters in the desert environment in the desert environment cause a decrease in cause a decrease in wildflower diversitywildflower diversity??

Example Hypothesis:Example Hypothesis:

If If grain-eatersgrain-eaters are eliminated from the environment by a are eliminated from the environment by a fence, then the fence, then the wildflower diversitywildflower diversity will increase by 20%. will increase by 20%.

Independent VariableIndependent Variable Dependent VariableDependent Variable

Write so anyone knows what you are saying!!!!!!!Write so anyone knows what you are saying!!!!!!!

Other StuffOther Stuff On the Scientific Method Quiz, if your grade is:On the Scientific Method Quiz, if your grade is:

13-14 = Awesome Job!!13-14 = Awesome Job!! 11-12 = Good, but needs some work.11-12 = Good, but needs some work. 7-10 = OK, but what are you at a loss about?7-10 = OK, but what are you at a loss about? 0-6 = Get help before the test Wednesday!!!0-6 = Get help before the test Wednesday!!!

On the Astronomy Quiz, if your grade is:On the Astronomy Quiz, if your grade is: 19-20 = Stellar Performance!!19-20 = Stellar Performance!! 18 = Awesome Job!!18 = Awesome Job!! 15-17 = Good, but needs some work.15-17 = Good, but needs some work. 9-14 = Ummmhhhh I think you need to study!!!9-14 = Ummmhhhh I think you need to study!!! Below a 9= Seek help before Wednesday test!!!Below a 9= Seek help before Wednesday test!!!

The Golden Age AstronomersThe Golden Age Astronomers

Aristotle(384-322BC)

The Earth is round.

Aristarchus(312-230BC)

1st to believe in heliocentric

universe