Download Astronomy

Astronomy
Chapter 22-25
Warm Up: Sept 7
http://www.youtube.com/watch?v=jRXQsQ
KGqIU – creepy twinkle
 http://www.youtube.com/watch?v=yCjJyiq
pAuU –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?
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2
Time Line
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Create a time to include each of the following
people (include their discovery).
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Aristotle
Eratosthenes
Hipparchus
Aristarchus
Claudius Ptolemy
Nicolaus Copernicus
Tycho Brahe
Johannes Kepler
Galileo Galilei
Sir Isaac Newton
What is the Golden Age of
Astronomy?
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The shift away from
the idea of a
Geocentric Universe.
What is Modern Astronomy?
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Nicolaus Copernicus
(1473-1543)
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Earth is just a planet
Universe is sun centered
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Mercury, Venus, Earth, Mars,
Jupiter, and Saturn
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Circular orbits around sun
Tycho Brahe (1546-1601)
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Used pointers to estimate
distance
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Pointers think big
protractor
Mentor Kepler
Who was Johannes Kepler
(1571-1630)?
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Brahe’s observations of Mars
Noticed that the orbit was not Circular
 Kepler used his Q&A’s to form 3 Laws of
Planetary Motion
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1st Law
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Ellipse (Oval)
2
foci
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Star
Laws of Planetary Motion
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2nd Law
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Sun sweeps over
equal areas in the
same amount of time.
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Close to sun faster
Away from sun slower
3rd Law
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Orbital Period (time) of
planet is proportional
to distance from the
sun (P2=d3),
expressed in AU units
(1AU = 1.5Million Km)
Who is Galileo Galilei?(15641642)
 Telescope
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Behavior of moving objects
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Observation supported Copernicus’s view of the
universe
 Moons
of Jupiter (4) = Earth is not the center of all
universal motion
 Planets are circular disc = must be Earth-like
 Venus has phases like the moon = orbits light source
(sun)
 Moon’s surface not smooth = validated others who
named areas based on features (Sea of Tranquility)
 Sun has dark regions = tracked movement est.
rotation period of sun under 1 month
What is the Law of Universal
Gravitation?
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Sir Isaac Newton (1642-1727)
 Kepler “some force pushes the planets along their
orbits”
 Galileo “no force is required to keep an object in
motion”
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Inertia
Every body attracts directly proportional to
mass & inversely proportion to distance2 b/w
the bodies
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Revised Kepler’s 3rd law (mass)
What are Earth Motions?
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Rotation
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Spinning on axis (day/night)
 Solar
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day
noon to noon
 Sidereal
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day
Based on a distant star
 23hr 56 min
 Distance to the stars change by tiny increments
 Sun changes by 1° a day
Earth Motions Cont.
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Revolution
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Moving around another body
 Distance
of the sun to the Earth @150 million km
 Elliptical Orbit
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Perihelion @ January 3
 147 million km
Aphelion @July 4
 152 million km
Earth Motions Cont.
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Precession
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Change in tilt of axis
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Changes North Star
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Polaris to Vega
Nutation
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23.5° always the same
Slow @ 26 000 years
Wobbling around the axis
Caused but the moon’s pull
Slight seasonal change.
Remember: Galaxies on the move!
What are Axis & Seasons?
Why do different season exist?
Axis & Seasons cont.
Moon (Satellite) Motions
Revolution = 1month (29 ½ days)
 Ave. distance = 384 401Km (6%)
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Perigee = closest to Earth
 Apogee = farthest
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Phases of the Moon
Waxing
 Waning
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How do Eclipses work?
What is Barycenter?
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The center of mass is the balance point
between two orbiting bodies, like a
seesaw.
The Sun
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Average Star
Some Stats:
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Diameter = 109
Earth diameters
Volume = 1.25
million times Earth’s
Mass = 332,000
times Earth’s
Density = 1/4th of
solid Earth
Sun Structure
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Structure
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the Solar Interior
Photosphere
2 Atmospheric Layers
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Chromosphere
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Prominences
Corona
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Solar Winds
Solar Flares & Sunspots
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Solar Flares
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Auroras
Sunspots
11 year cycle
 Last days to weeks
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The Solar interior
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Nuclear Fusion
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E=mc2
It takes very little
hydrogen to make a
lot of energy.
Most of the hydrogen
is not converted to
energy.
Other Stuff
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Scientific Methods Quiz Redo
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A problem is a question to be answered!!!!!
Answer the QUESTION!!!!!!!!!!!!!!!!
Do not for get the problem/hypothesis relationship!!!!!
Example Problem:
Does the presence of grain-eaters in the desert environment
cause a decrease in wildflower diversity?
 Example Hypothesis:
If grain-eaters are eliminated from the environment by a
fence, then the wildflower diversity will increase by 20%.
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Independent Variable
Dependent Variable
Write so anyone knows what you are saying!!!!!!!
Other Stuff
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On the Scientific Method Quiz, if your grade is:
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13-14 = Awesome Job!!
11-12 = Good, but needs some work.
7-10 = OK, but what are you at a loss about?
0-6 = Get help before the test Wednesday!!!
On the Astronomy Quiz, if your grade is:
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19-20 = Stellar Performance!!
18 = Awesome Job!!
15-17 = Good, but needs some work.
9-14 = Ummmhhhh I think you need to study!!!
Below a 9= Seek help before Wednesday test!!!
The Golden Age Astronomers
Aristarchus
(312-230BC)
Aristotle
(384-322BC)
The Earth
is round.
1st to believe in
heliocentric
universe