Download Sun, Earth, Moon Astronomy 1 — Elementary Astronomy LA Mission College Spring F2015

Sun, Earth, Moon
Astronomy 1 — Elementary Astronomy
LA Mission College
Spring F2015
Cartoon of the Day
“From now on we live in
a world where man has
walked on the Moon. It's
not a miracle; we just
decided to go. “
-- Tom Hanks
Astronomy 1 - Elementary Astronomy
LA Mission College
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Announcements
COLLEGE OF THE CANYONS • Canyon Country Campus
Join us for a
•
•
CoC Star Party
tomorrow
Grading up to date!
STAR FORMATION: Light Beyond The Visible
Presented by Dr. Luisa Rebull
Research Scientist, SSC and IRSA, IPAC, Caltech
Featuring:
• Hands-on interactive demonstrations and activities
• COC student clubs and academic departments
highlighting innovative approaches to
understanding the science that governs the universe
• Gaze at the stars through a variety of telescopes
Friday,
OCT 16
7 – 9:30 p.m.
Carl A Rasmussen Amphitheater
College of the Canyons Canyon Country Campus
17200 Sierra Highway, Santa Clarita, CA 91351
Tallest Tower
Building Competition
Sign-up online!
www.canyons.edu/Offic
es/
CCC/Pages/StarParty.a
spx
LA Mission College
F THE C
• COLLE
N
A
NS •
YO
Astronomy 1 - Elementary Astronomy
CA
www.canyons.edu/ccc
EO
N
For more information visit
G
Food and beverages
will be available for purchase
YO
N
RY
•
HW Kepler, Gravity
Light due
Star
Party
C OU
NT
Levine F2015
Last Class
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Midterm debrief
Multi-wavelength Astronomy
Intro to the Solar System
LT Sun Size (completed, not debriefed)
Astronomy 1 - Elementary Astronomy
LA Mission College
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This Class
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•
•
•
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Grade Status
Debrief LT Sun Size & do questions
Sun
Earth
Moon
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
Grade Status
Astronomy 1 — Elementary Astronomy
LA Mission College
Spring F2015
Grade Status
Letter
Midterm
Course
A
9
13
B
7
18
C
14
8
D
12
4
F
7
6
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
Debrief LT Sun Size
Astronomy 1 — Elementary Astronomy
LA Mission College
Spring F2015
The Sun has a diameter of approximately 1.4 million
kilometers. Roughly how many Earths would fit across
the diameter of the Sun?
A. 10
B. 100
C. 1000
D. 10,000
E. 1 million
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
Let’s Practice
sunspots. How does the size of Earth compare to the size of the sunspot that is identified on
the right side of the image of Sun?
The image
at right shows a
a) Earth and the sunspot are about the
size. Sun. The dark
picture same
of the
b) The sunspot is much, much larger than
spots located
on this image
Earth.
c) The sunspot is much, much smaller than
are sunspots.
How does the
Earth.
size of Earth compare to the
size of the sunspot that is
identified on the right side of
the image of Sun?
2) Which statement do you think best represents the size comparison between the diameter of
the Sun and the distance between the Moon and Earth? The Sun’s diameter is
a) smaller than the distance between the Moon and Earth.
b) approximately equal to the distance between the Moon and Earth.
c) larger than the distance between the Moon and Earth.
A. Earth and the sunspot are about the same size.
B. The sunspot is much, much larger than Earth.
3) If you were constructing a scale model of the solar system that used a Sun that was the size
of a basketball (approximately 12 inches in diameter), which of the following lengths would
most closely approximate the scaled distance between Earth and the Sun?
a) 3 feet (length of an outstretched arm)
b) 10 feet (height of a basketball goal)
c) 100 feet (height of an 10 story building)
d) 300 feet (length of a football field)
C. The sunspot is much, much smaller than Earth.
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
Which statement do you think best represents the size
comparison between the diameter of the Sun and the
distance between the Moon and Earth? The Sun’s
diameter is
A. smaller than the distance between the Moon and
Earth.
B. approximately equal to the distance between the
Moon and Earth.
C. larger than the distance between the Moon and
Earth.
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
If you were to construct a scale model of the solar
system that used a 2 cm cherry to represent the Moon,
how large of a ball would you need to represent the
Sun?
A. 4cm
B. 30cm
C. 110 cm
D. 440 cm
E. 880 cm
Astronomy 1 - Elementary Astronomy
LA Mission College
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The Sun
Astronomy 1 — Elementary Astronomy
LA Mission College
Spring F2015
THE SUN IS A STAR
What is a star?
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A sphere of hot gas
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mostly hydrogen & helium
Interior hot enough to undergo nuclear fusion in core
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core above 107 K = 10 million K (18 million °F)
Astronomy 1 - Elementary Astronomy
LA Mission College
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Why Stars Shine
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Visible Sun is a hot
layer of gas
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about 5800 K (5525°C,
9980°F)
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not as hot as the center!
Gives off light the same
way that hot metal
glows red, yellow or
white
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Thermal radiation or
blackbody
This is why stars have
different colors
Astronomy 1 - Elementary Astronomy
LA Mission College
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Basic Data
http://www.kidsgeo.com/geography-for-kids/0003-how-big-is-the-earth.php
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Fairly average star
It rotates
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faster at the equator (25 days) than at the poles (31 days)
Entirely gas: Hydrogen (80%) and Helium (19%)
Central Temperature 15,000,000 K
Surface Temperature 5800 K
Astronomy 1 - Elementary Astronomy
LA Mission College
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What Type of Star is the Sun?
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Main Sequence Star
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most stars spend most
of their “life” on the Main
Sequence
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energy source
thermonuclear fusion
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H fusing to He in the core
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
What Type of Star is the Sun?
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Spectral Type G2
Lifetime on Main
Sequence 10 billion
years
Astronomy 1 - Elementary Astronomy
LA Mission College
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The structure of the Sun
Astronomy 1 - Elementary Astronomy
LA Mission College
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The structure of the Sun
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Core
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compact: center to about 25% radius
15 million K
atoms completely ionized
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e- “blasted off”
Where thermonuclear fusion is taking place.
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
The structure of the Sun
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Radiative zone
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0.25 - ~ 0.7 solar radii
Energy from core
transferred by EMR
Convective zone
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above radiative zone
Energy transferred to
surface by convection
Astronomy 1 - Elementary Astronomy
LA Mission College
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Convection
Cool gas
sinking down
Astronomy 1 - Elementary Astronomy
Bubbles of hot
gas rising up
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Let’s Practice
The Sun’s Luminosity comes primarily from
A. chemical burning
B. gravitational contraction
C. nuclear fusion
D. nuclear fission
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
The energy produced by the Sun is produced
A. in a very small region at the center of the Sun
B. Uniformly throughout the Sun
C. At the surface of the Sun
Astronomy 1 - Elementary Astronomy
LA Mission College
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THE OUTER LAYERS OF THE
SUN
The structure of the Sun
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Photosphere
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Visible surface of the
Sun
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Apparently smooth layer
of gas
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500 km thick
5800 K
Sunspots
Astronomy 1 - Elementary Astronomy
LA Mission College
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Granulation
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Up close, photosphere has a mottled appearance
(granulation) due to convection cells.
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These cells form and fade and shift on a time scale of
tens of minutes.
Astronomy 1 - Elementary Astronomy
LA Mission College
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Sunspots
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well-defined surface
areas that appear
darker than their
surroundings
because of lower
temperatures.
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Associated with sun’s
magnetic field
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convection is
inhibited by strong
magnetic fields,
reducing energy
transport from the hot
interior to the surface
Astronomy 1 - Elementary Astronomy
http://
LA Mission College
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The structure of the Sun
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Chromosphere
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Atmospheric layer
above the photosphere.
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1000x fainter than the
photosphere, but hotter!
Astronomy 1 - Elementary Astronomy
LA Mission College
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The structure of the Sun
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Chromosphere
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Pink color during a total
eclipse.
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Filaments (dark regions)
& Spicules/prominences
(jets).
Astronomy 1 - Elementary Astronomy
LA Mission College
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Solar Prominence
Astronomy 1 - Elementary Astronomy
LA Mission College
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Let’s Practice
Sunspots appear dark because
A. They are holes in the photosphere allowing a view of
deeper layers
B. Are large opaque structures that block the light from
the interior
C. Are slightly cooler than the surrounding areas,
appearing dimmer
D. Are burning holes in your retina
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
THE CORONA, SOLAR WIND
AND SOLAR WEATHER
The structure of the Sun
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Corona
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Outermost
atmospheric layer.
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Extending outwards
20 times the Sun’s
radius.
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Heated by magnetic
field interactions.
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solar wind
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300 - 1000 km/s
Loses 10 million tons/yr
http://antwrp.gsfc.nasa.gov/apod/ap080920.html
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
Solar Weather
(Ultraviolet images)
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In addition to sunspots, solar activity results in
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Solar flares
Aurora Borealis
Coronal Mass Ejections
Geomagnetic Storms
http://spaceweather.com/, http://www.swpc.noaa.gov/
Astronomy 1 - Elementary Astronomy
LA Mission College
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Aurora Borealis
Astronomy 1 - Elementary Astronomy
LA Mission College
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Solar Weather and Humans
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Solar flares
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Coronal Mass Ejection
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really refer to increased brightness
Interferes with Satellites
Geomagnetic Storms
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In rare cases causes power grid issues
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
FATE OF THE SUN
Endgame for our Sun
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A star’s fate is pretty much determined at the moment of
it’s “birth” by its mass
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High mass stars, ~ 8x Sun, explode
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and the company it keeps
supernovae
Low mass stars like the Sun have a different fate
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Sun does NOT!!!!! “go supernova”
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
Main Sequence to Red Giant
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After the core becomes
depleted of H, the Sun
will become a red
giant
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He core
H burning shell
A much larger, cooler
star
Ar#sts concept of the Sun as a red giant: Image: ESA
Earth, in all likelihood,
gets swallowed up
Astronomy 1 - Elementary Astronomy
LA Mission College
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Red Giant to White Dwarf
Spitzer Space Telescope Image of a PN the Helix Nebula
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Eventually the red giant
exhausts the H in its
shell
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throws off up to half its
mass
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“planetary nebula”
Astronomy 1 - Elementary Astronomy
LA Mission College
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Fading away...
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Core becomes a white
dwarf
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Squeezed into size of
Earth
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Maximally compressed
into a degenerate gas
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In isolation, very slowly
cools and fade away
Astronomy 1 - Elementary Astronomy
Artist’s concept
Image ESA/NASA
LA Mission College
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Let’s Practice
The Sun will ultimately
A. Go Supernova
B. Become a white dwarf
C. Become a black hole
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
Which of the following are the most potentially
damaging consequences of solar activity
A. Solar flares & Aurora Borealis
B. Coronal Mass Ejections & Geomagnetic storms
C. Promenences and Spicules
Astronomy 1 - Elementary Astronomy
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The Earth as a Planet
Astronomy 1 — Elementary Astronomy
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Comparison of the “Terrestrial” Planets
Astronomy 1 - Elementary Astronomy
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The “Habitable Zone”
www.astrobio.net
•
In astronomy and astrobiology, the habitable zone is
the region around a star where a planet with
sufficient atmospheric pressure can maintain
liquid water on its surface.
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
Earth’s Statistics
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Equatorial Diameter = 12,756 km
Mass = 5.98 x 1024 kg
av. density = 5.5 g/cc
surface T = -50°C to +50°C
a = 1.00 AU
P = 1.00 year
e = 0.0167
Astronomy 1 - Elementary Astronomy
LA Mission College
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Earth’s Uniqueness
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Every major process on any rocky world in our solar system is represented
in some form on Earth.
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Unique in 2 important ways
1. Surface water (75% of the surface is water)
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No other SS body has surface water currently
2. Life
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No other SS body has been found to have life. Yet.
Astronomy 1 - Elementary Astronomy
LA Mission College
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Earth’s Early History
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Formed 4.6 billion years
(4.6 x 109) ago from the
inner solar nebula.
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4 Stages of Evolution:
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Differentiation
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Flooding
Heavy Bombardment:
Cratering
Slow Surface Evolution
Astronomy 1 - Elementary Astronomy
LA Mission College
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Earth’s Structure — Core
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Hot as the Sun’s surface (~6000 K)
Solid inner core
liquid core surrounding it
Source of Earth’s magnetic field
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Dynamo effect
Astronomy 1 - Elementary Astronomy
LA Mission College
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Earth’s Structure — Mantle
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Solid (“plastic”) Mantle
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As in deformable, not as in manmade
Astronomy 1 - Elementary Astronomy
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Earth’s Structure — Crust
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Solid
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Thicker under land (60 km)
thinner under oceans (10 km)
Brittle: Broken into tectonic plates
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only terrestrial planet with plate tectonics
Astronomy 1 - Elementary Astronomy
LA Mission College
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Earth’s Magnetic Field
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Is Useful
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Likely helps birds & fish know where N and S are for migration
Compasses
Most importantly, it protects us from the solar wind
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which would otherwise slowly strip the Earth’s atmosphere away...which would
NOT be good!
Is generated by the dynamo effect
Astronomy 1 - Elementary Astronomy
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Magnetic Field via Dynamo Effect
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2 Key components
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Liquid conductor
Rotation
Earth
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ample liquid iron outer
core, plus
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fairly brisk 24 hr
rotation, yields
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strong magnetic field
Astronomy 1 - Elementary Astronomy
image from: http://www.abc.net.au
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The Core and the Dynamo
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Earth’s core consists
mostly of iron + nickel
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high electrical
conductivity.
A conductor in motion
creates a magnetic field
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The liquid core convects
and the Earth Rotates
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Results in a dipole field
Astronomy 1 - Elementary Astronomy
LA Mission College
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PLATE TECTONICS
Plate Tectonics
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Plates are moved by convective motion in the mantle
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hot material rises and cools, cool material sinks
Astronomy 1 - Elementary Astronomy
LA Mission College
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Earth’s Tectonic History
Astronomy 1 - Elementary Astronomy
LA Mission College
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LET’S PRACTICE
If the Earth’s rotation were to slow down drastically
which of the following would most likely happen?
A. Runaway Greenhouse effect, leading to unsurvivable
surface temperatures
B. Diminishment of Earth’s magnetic field, leading to loss of
protection from the solar wind
C. Diminishment of atmospheric friction, leading to dramatic
cooling of the surface
D. Diminishment of gravitational force, leading to loss of the
Moon.
Astronomy 1 - Elementary Astronomy
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Plate tectonics exists on Earth because _____.
A. convection in the mantle causes motion
B. the crust is thin and broken into pieces
C. both of these
D. neither of these
Astronomy 1 - Elementary Astronomy
LA Mission College
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EARTH’S TIMELINE
History of Geological Activity
Astronomy 1 - Elementary Astronomy
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Earth’s Atmosphere
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76% Nitrogen, 23% Oxygen, 1.3% Argon & a smattering of
other stuff
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(water and carbon dioxide included).
Ozone (O3) protects the surface from UV radiation (26 km up).
Carbon Dioxide i s a “greenhouse gas:” it is transparent to
visible light, but opaque to infrared light
Astronomy 1 - Elementary Astronomy
LA Mission College
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Evolution of Atmosphere
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Primordial Atmosphere
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Whatever was outgassed by the geologic activity (volcanoes)
of ~4 billions years ago.
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carbon dioxide (CO2), nitrogen, water vapor.
The CO2 levels decreased
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As Earth cooled, water vapor condensed. Oceans formed!
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The CO2 reacted with other elements in the water
The oceans absorbed CO2 (CO2 is soluble in water… think
carbonated drinks!)
Astronomy 1 - Elementary Astronomy
LA Mission College
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Evolution of Atmosphere
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O2 levels increased
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Initially, any oxygen present reacted with minerals to form iron
oxide, etc…
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The rise of oxygen levels in the Earth’s atmosphere is tied
to life.
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Specifically photosynthesis
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evolved 2.7 - 2.4 billion years ago
picked up when the oceans developed plant life 2-2.5 billion years ago
Oxygen exists because of life, not vice versa!
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
Where Water Came From
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Not completely well understood. Several hypotheses:
Older hypothesis: Primordial content and Vulcanism
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When a volcano erupts, 50-80 % of the gas is water vapor.
Newer understanding: Primordial outgassing
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Earth formed so rapidly that it was substantially heated by the
impacts of infalling material, as well as by radioactive decay.
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Molten surface -> continuous outgassing
straight to the volcanic “ secondary atmosphere” without a
hydrogen- rich primeval atmosphere.
Some of the water may have arrived late in the formation as a
bombardment of volatile-rich planetesimals
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studies of Comet LINEAR, which broke up in 1999 as it passed near
the sun, support this
Astronomy 1 - Elementary Astronomy
LA Mission College
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The Moon
The Moon
Astronomy 1 — Elementary Astronomy
LA Mission College
Spring F2015
Importance of the Moon
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Galileo Image taken on
way to Outer Solar
System
Moderates wobble of
Earth’s axis
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stabilizes climate
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Tides
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Only place aside from
Earth we have visited in
person
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Lunar Ranging
Image Credit: NASA
Cultural and Historical
importance
Apollo 16, Image Credit: NASA
Astronomy 1 - Elementary Astronomy
LA Mission College
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CHARACTERISTICS OF THE
MOON
Moon
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Equatorial Diameter = 3476 km
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mass = 7.35 x 1022 kg
average density = 3.4 g/cc
surface temp = -170°oC to
+130°C
•
•
•
Earth
a = 384,400 km (from Earth!)
P = 29.5 days (around Earth!)
e = 0.055 Astronomy 1 - Elementary Astronomy
•
•
•
•
•
•
Equatorial Diameter = 12,756
km
mass = 5.98 x 1024 kg
average density = 5.5 g/cc
surface temp = -50°C to +50°C
a = 1.00 AU
P = 1.00 y
e = 0.0167
LA Mission College
Levine F2015
Key Characteristics of the Moon
Credit: NASA/GSFC/Arizona State
University
Oblique View of the Lunar Crater Tycho
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No magnetic field
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No atmosphere
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Small core, no iron
Too small & hot to hold onto gases
gas molecules readily reach escape velocity!
Very dry
•
•
no sedimentary rock
some ice may exist under the surface
Astronomy 1 - Elementary Astronomy
LA Mission College
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The Moon: The View from Earth
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Tidally coupled to the
earth
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rotation = revolution
always see same side
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Heavily cratered
highlands
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Smoother, darker
lowlands
•
•
•
Farside from
Nearside
fromLRO
LRO
maria (“seas”)
Credit: NASA/
GSFC/Arizona
State University
flooded by lava
Cool
Astronomy 1 - Elementary Astronomy
LA Mission College
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Lunar Craters
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Numerous!
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>300,000
•
Named after
people:
scholars,
scientists,
explorers
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Typical crater
morphology
Astronomy 1 - Elementary Astronomy
Plato
Mare
Imbrium
Aristarchus
Oceanus
Kepler
Procellarum
Mare
Serenitatis
Copernicus
Mare
Tranquillitatis
Mare
Crisium
Mare
Nubium
Tycho
LA Mission College
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Lunar Maria
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large, dark, basaltic
plains
•
•
•
lava flooded low-lying
areas
more prevalent on near
side
Plato
Mare
Imbrium
Aristarchus
Oceanus
Kepler
Procellarum
Mare
Serenitatis
Copernicus
Mare
Tranquillitatis
Mare
Crisium
Mare
Nubium
1.2-4.2 billion y.o.
•
•
Tycho
radiometric dating
crater counting
Astronomy 1 - Elementary Astronomy
LA Mission College
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LET’S PRACTICE
There is very little atmosphere on the Moon because
A. dry rocks on the moon absorb gases as soon as they
are created.
B. it was blown away by meteor bombardment.
C. its low mass and high temperature allowed most
gases to escape.
D. the gravitational tidal forces from the Earth stripped
it away.
Astronomy 1 - Elementary Astronomy
LA Mission College
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The Moon
A. always points the same face towards the Sun.
B. does not rotate.
C. rotates at the same rate as the Earth rotates -once per day.
D. rotates at the same rate as it revolves around
Earth -- once per month.
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
LUNAR EXPLORATION
History of Lunar Exploration
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•
1st visited by the USSR's Luna 1 and Luna 2 in 1959.
These were followed by a number of U.S. and Soviet
robotic spacecraft. US sent:
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•
•
•
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Rangers (1961-1965) were impact probes,
Lunar Orbiters (1966-1967) mapped the surface
Surveyors (1966-1968) were soft landers.
Apollo program -- Men on the Moon
Lunar exploration resumed in the 1990s
•
Clementine & Lunar Prospector
Astronomy 1 - Elementary Astronomy
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Manned Lunar Exploration
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May 25, 1961 -- President John Kennedy committed
the United States to landing a human being on the
moon by 1970.
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Vehicle hefty enough to get to moon would be difficult to
land: Two-module design with “disposable” lander
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•
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•
Command module
The lunar landing module ( LM )
The first human- piloted lunar landing was made July 20,
1969.
July 1969 -- December 1972,:
•
•
12 people reached the lunar surface
collected 380 kg ( 840 lb) of rocks and soil
Astronomy 1 - Elementary Astronomy
LA Mission College
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Apollo Landing Sites
•
First Apollo
missions landed
on safe, smooth
terrain.
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•
Apollo 11: Mare
Tranquilitatis;
lunar lowlands
Later missions
explored more
varied terrains.
•
Apollo 17: TaurusLittrow; lunar
highlands
Astronomy 1 - Elementary Astronomy
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The Apollo Missions
•
Hoax Believers, please check out Mr. “Bad Astronomy” Phil Platt’s extensive rebuttal:
•
•
http://www.badastronomy.com/bad/tv/foxapollo.html
And this filmmaker’s assessment of why faking it would have been harder than making it
•
http://www.space.com/19531-moon-landings-faked-filmmaker-says-not-video.html
Astronomy 1 - Elementary Astronomy
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Moon Landing Remastered
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http://video.nationalgeographic.com/video/news/spacetechnology-news/1969-moonlanding-vin/
Astronomy 1 - Elementary Astronomy
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Moon Rocks
Vesicular (= containing holes
from gas bubbles in the
lava) basalts, typical of
dark rocks found in
maria
•
Breccias (= fragments of
different types of rock
cemented together), also
containing anorthosites (=
bright, low-density rocks
typical of highlands)
Older rocks
become pitted
with small
micrometeorite
craters.
Igneous (solidified lava)
•
No sedimentary rock
Astronomy 1 - Elementary Astronomy
LA Mission College
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LUNAR FORMATION
Must Explain
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•
•
•
•
•
Similar oxygen isotopic composition to Earth
But different chemical composition -- low density
No magnetic field
All igneous rock
Same age as Earth
Maria and Highlands
Astronomy 1 - Elementary Astronomy
LA Mission College
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Moon formation
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Fission Hypothesis
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Condensation Hypothesis
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Earth & Moon formed as a double planet system
Capture Hypothesis
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•
Earth broke in two (if it were spinning quickly enough)
Earth gravitationally captured a pre-existing body
Large-impact hypothesis
•
Early earth and moon formed from the glancing collision of
two protoplanets
•
Resulting large body became the earth and ejected debris formed
the moon
•
Could have caused Earth’s 23° tilt
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
Large Impact Hypothesis
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Impacting body about the size of Mars — Theia
Impact heated material enough to melt it
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Collision not head-on
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consistent with “sea of magma”
Large angular momentum of Earth-moon system
Collision after differentiation of Earth’s interior
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Different chemical compositions of Earth and moon
Earth absorbed iron core of impactor
Molten remnant material coalesced into Moon
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
LET’S PRACTICE
Which proposed explanation for the Moon’s origin was
ruled out when the Apollo mission revealed similar
abundances of isotopes of oxygen in lunar rock as on
Earth?
A. that the Moon broke off from the Earth
B. that the Moon and Earth formed together out of the
same material
C. that the Moon was a passing body that was
gravitationally captured by the Earth
D. that the Moon was formed when a large object
impacted the proto-Earth
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
WRAP-UP
Topic for Next Class
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Mercury, Venus, Mars
Greenhouse effect
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
Reading Assignment
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Astro: 7
Astropedia: 8
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015
Homework
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No new HW yet
Astronomy 1 - Elementary Astronomy
LA Mission College
Levine F2015