Transcript Earth`s Motions

Earth’s Motions
By Langley
How does the Earth move?
• 1A: Rotation: One spin on its axis
1B: 360 degree / 24 hours
1C: 15 degrees / hour
1D: Direction: West to East
(Counterclockwise)
1E: Earth’s rotation makes it appear that the
stars are moving.
Proof that the Earth Rotates
• 2A. Coriolis Effect: Objects in the Northern
Hemisphere are deflected to the right.
• Coriolis Effect Merry-Go-Round
Coriolis Effect
Proof that the Earth Rotates
• 2B. Foucault Pendulum: the pendulum
swings in one plane; it knocks over
markers because the Earth is spinning
beneath it.
Proof That the Earth Rotates
• 2C. Shadows – change throughout the day
• Shortest: When the sun is highest (solar
noon)
• Longest: Sun is lowest (Sunrise & Sunset)
Shadows in New York
• 3. During solar noon, shadows point north
in the northern hemisphere because the
sun is in the southern sky (since we live in
the Northern Hemisphere)
Partner Discussion
• 4A. What is the nearest star to Earth?
• 4B. Why does it appear to rise/set?
• 4C. Where does it rise? Set? (North, West,
East, or South)
• 4D. What is the shape of its path across our
sky?
A.
B.
C.
D.
Sun’s Path
• Interactive - Notice the height of the Sun
during each season
Vocab
• Apparent Motion:
• Rotation:
• Coriolis Effect:
• Celestial Object:
Objectives
1. Explain Rotation:
3. Calculate the apparent rate of motion of
celestial objects caused by rotation.
2. Objectives
• Foucault Pendulum – if the Earth did not
rotate a large pendulum would continually
travel over the same spots, however, the
pendulums path appears to change due to
earth’s rotation
• Coriolis Effect – Winds are deflected to the
right as a result of rotation
Star Trails
Astronomy A
Earth in Space
By Mr. Ruder
Starry Night
• Planetarium
1. Which Direction is this
person facing?
2. What is the name of the
star in the center of the
stars?
3. Why does the North Star
appear to not move?
Polaris
Polaris
3.The
North Pole
is Aligned
with Polaris
4. Star Trails
• Rise in East
Set in West
• 6. Draw the star trails around Polaris.
Path Around Polaris
• 6 Hour Exposure =
90 Degrees
• 12 Hour Exposure
= 180 Degrees
Which Direction is this
person facing? Is this
person facing North?
How do you know this
person is not facing
North?
How much time
passed to take this
picture?
Why is this star not following the
concentric pattern of the other stars?
Where do you think this squirrel is located in the world
to see these star trails? What latitude?
Equator
South
North
• Which direction are you facing?
Partner Discussion
• 7A. Why does it appear that the stars
(including the sun) move?
• 7B. How fast do they appear to move?
• 7C. How long does it take for a star to
appear to complete one path around the
earth?
Resources
•
•
•
•
•
•
•
•
•
•
•
•
•
http://images.google.com/imgres?imgurl=http://www.astro.uiuc.edu/~kaler/arc/foucault.jpg&imgref
url=http://www.astro.uiuc.edu/~kaler/arc/sk051603.html&h=416&w=613&sz=50&hl=en&start=3&tb
nid=9vWqnJJjwVkMUM:&tbnh=92&tbnw=136&prev=/images%3Fq%3Dfoucault%2Bpendulum%2
6ndsp%3D20%26svnum%3D10%26hl%3Den%26rls%3DHPIA,HPIA:200618,HPIA:en%26sa%3DN
http://mxp.physics.umn.edu/s05/Projects/S05SphericalPendulum/foucault-pendulum.jpg
http://www.nmm.ac.uk/upload/img/shadow-stick.gif
http://www.morehead.unc.edu/Shows/EMS/images/Sun's%20Path.jpg
http://www.madison.k12.wi.us/planetarium/sunpath.gif
http://www.modelsdirect.com/news/summer_newsletter_2006/sun-blue-sky-9927438.jpg
http://upload.wikimedia.org/wikipedia/en/thumb/5/53/Chatham_sunrise.jpg/250pxChatham_sunrise.jpg
http://hea-www.harvard.edu/ECT/the_book/Chap2/EarthTilt.gif
http://aer.noao.edu/figures/v03i01/00097_00069.jpg
http://www.racgallery.com/d/361-5/dehoog.jpg
http://www.cip.physik.uni-muenchen.de/~gumpp/astropics/orion.jpg
http://antwrp.gsfc.nasa.gov/apod/image/9809/northpole_malin.jpg
http://starchild.gsfc.nasa.gov/Images/StarChild/questions/precession_animation.jpg
Angle of Incidence
Astronomy A
Reasons for the Seasons
1. Which rays
from the sun
are direct and
which ones are
indirect rays?
Label them.
What point is
receiving the
most Energy?
Indirect Ray
2. What is a
direct ray?
Which direction
would an
observer have
to look to see
the sun on the
equator?
Direct Ray
Which direction would an observer have
to look to see the sun at 600 Latitude?
3. What happens to the amount of energy
received in one location when the angle
is less than 900?
4. Why does it get colder in an area that
receives light at a lower angle of
incidence?
Which hemisphere is
experiencing Summer?
Which hemisphere is
experiencing Winter?
N
Direct or
Direct
Indirect
Ray
Ray?
Warmer
What is the
temperature here?
Where do these guys
look to see the Sun
in the Sky?
Direct or
Indirect
Indirect
Ray
Ray?
Colder
What is the
temperature here?
Earth Sun Relationships
Animation from Internet
Click on the Picture below
http://esminfo.prenhall.com/science/geoanimations/animations/
01_EarthSun_E2.html
Earth’s Revolution
By Langley
Partner Discussion
• 1A. What is revolution?
• 1B. How long does it take for Earth to revolve
around the sun?
• 1C. Which seasons have the most sunlight?
Least? (Winter? Spring? Summer? Fall?)
• 1D. Why is summer warmer than winter?
What causes seasons?
• Tilt of Earth’s axis = 23.5 degrees. The
sun’s parallel rays are at 90 degrees in
one place at one time.
• Earth’s revolution around the sun = 365
days (1 year) or about 1 degree per day
• Parallelism of Earth’s axis in orbit = The
Earth’s axis is always parallel to itself in
orbit.
• Rotation on the Earth’s axis = 1 Day
Reasons for Seasons
Partner Discussion
• 3A. How
can you tell
if it is
summer or
winter?
• 3B. What is
Solstice?
• 3C.
Equinox?
Solstice
• 4. Solstice: When the sun is at its
minimum or maximum height in the sky
– 5. Winter Solstice: Lowest = Dec. 21st
– 5. Summer Solstice: Highest = June 21st
Move to Seasons Slides
Equinox
• 6. Sun hits
directly on
Equator
• 6. Equal hours
of daylight /
darkness (12
hours)
• 7. Vernal
Equinox =
March 21st
• 7. Autumnal
Equinox = Sept.
23rd
9. Why are the season labeled the
opposite?
Partner Discussion
• 10A. Which
direction does Earth
rotate around the
sun?
• 10B. Why are there
two seasons
labeled on the
diagram?
• 10C. How does the
distance between
the Earth and Sun
affect the seasons?
What position is the Earth in
relation to the sun to cause
seasons?
• A. North Pole tips toward the sun = Summer
• B. North Pole tips away from the sun = Winter
• 11. ***The Earth is closer to the sun in winter***
The heat from the vertical rays at 23.5 N is more
powerful at heating the Earth then being close to
the Earth.
• 12. Perihelion:
• 13. Aphelion:
Daylight and Temperature
• 14. Solar noon is when the sun is highest
in the sky and when the Earth is getting
the most direct rays of the sun.
• 15. ***Not the same as noon on the
clock***
Resources
• http://www.wcer.wisc.edu/NCISLA/MUSE/earth-moonsun/materials/build/material2F/seasons.gif
• http://www.learner.org/jnorth/images/graphics/m/mc-earth-orbit.gif
• http://images.google.com/imgres?imgurl=http://www.enchantedlearni
ng.com/subjects/astronomy/planets/earth/solstice/solsticediagram/ti
ny.GIF&imgrefurl=http://www.enchantedlearning.com/subjects/astro
nomy/planets/earth/Seasons.shtml&h=172&w=230&sz=10&hl=en&s
tart=4&tbnid=h_QQQgnPFcGIuM:&tbnh=81&tbnw=108&prev=/imag
es%3Fq%3Dsolstices,%2Bcar%26svnum%3D10%26hl%3Den%26rls%3DHPIA,HPIA:200618,HPIA:en
• http://planet-terre.enslyon.fr/planetterre/objets/Images/solstice/equinoxe.jpg
• http://www.webdesign.org/img_articles/5971/clockface.gif
• http://users.aber.ac.uk/how4/pictures/perihelion.gif
• http://calsolareng.com/image_files/content/photovoltaics/image5.gif
The Reasons for Seasons
Edward M. Murphy
Space Science for Teachers
2005
1. Day Night Cycle – Caused by
Earth’s Rotation
Rotation vs. Revolution
• Partner Discussion:
• 2A. What is the difference between
rotation and revolution?
• 2B. How long does it take for Earth to
rotate compared to revolve?
Rotation vs. Revolution (movie)
• 2. Rotation is the spin of an object about
its axis.
– The Earth rotates once a day (once every 24
hours).
• 3. Revolution is the orbit of one object
around another.
– The Earth revolves around the Sun every
365.26 days.
Evidence of Revolution
• See different constellations throughout the
year.
– Ex: March = Leo
– Ex: January = Gemini
5a. Where is the Sun?
5b. What time in Atlantic
Ocean/Pacific Ocean?
Path of the Sun Animations
in New York
6. Tropics: The sun is never directly
overhead North or South of the
Tropics
The Annual Path of the Sun
• 7. On the summer solstice:
– 7a. the Sun will appear directly overhead to someone
at 23.5 degrees north latitude. This latitude is called
the Tropic of Cancer.
– 7b. The Sun does not set for people within 23.5
degrees of the North pole (above the Artic circle)
– 7c. The Sun does not rise for people within 23.5
degrees of the South pole (below the Antarctic Circle).
– Sunlight on Poles
– 7d. New York experiences the longest days with the
strongest insolation. (16 hours daylight/ 9 hours
darkness)
Earth on June 21
Standing on the North Pole
Standing on the Tropic of Cancer
8. The Annual Path of the Sun
• On the autumnal/vernal equinox:
– 8a. The Sun will appear directly overhead to someone
on the equator at 0 degress latitude.
– 8b. Everywhere on Earth experience 12 hours of
daylight and 12 hours of darkness.
– Amount of Sunlight during the Seasons
Standing on the Equator
9. The Annual Path of the Sun
• On the winter solstice:
– 9a. The Sun will appear directly overhead to someone
at 23.5 degress south latitude, the Tropic of
Capricorn.
– 9b. The Sun does not set for people within 23.5
degrees of the South Pole (below the Antarctic Circle)
– 9c. The Sun does not rise for people within 23.5
degrees of the North Pole (above the Arctic Circle)
– 9d. New York: Experiences the shortest daylight and
the weakest insolation (9 hours daylight/ 16 hours
darkness)
Earth on December 21
Seasons Misconception
• Many people carry the misconception that the
seasons are due to the distance of the Earth
from the Sun. However, consider the following
facts:
– The Earth’s orbit around the Sun is nearly a perfect
circle. The Earth is slightly closer to the Sun in
January and farther from the Sun in July.
• Perihelion (closest to the Sun) is around January 3 when
Earth is about 91,405,436 miles from the Sun.
• Aphelion (farthest from the Sun) is around July 4 when Earth
is about 94,511,989 miles from the Sun.
Seasons Misconception
– While it is winter in the Northern hemisphere it
is summer in the Southern hemisphere. If the
seasons were due to our distance from the
Sun both hemispheres would have the same
seasons at the same time.
Orbit of the Earth
The Seasons
Season Facts
• 10a. The seasons are due to the tilt of the
Earth’s axis. Summer in Northern Hemisphere =
June 21 = when the northern hemisphere of the
Earth is tilted toward the Sun:
• 10b. In summer, the sunlight strikes the ground
more vertically than in December. The light is
spread out over less ground and heats the
ground better.
• 10c. The Sun is above the horizon for a longer
period of time.
Solar Illumination
• 11. Label Summer and Winter
Earth on June 22
Earth on December 22
A.M. and P.M.
• 12. At midday, the Sun is at it’s maximum
height.
• This occurs close to, or at, noon.
Tilt of the
Earth’s
Axis
The Moon
By Langley
Partner Discussion
• 1a. Explain what you know about the moon.
• 1b. How long does it take for the moon to
revolve around the Earth?
• 1c. What are the different phases called?
• 1d. What causes the moon phases?
Moon Information
•
•
•
•
2a. Earth’s Natural Satellite
2b. Probably made of iron and nickel
2c. Revolves around Earth in 29.5 days
2d. Moon = Moonth
Moon Phases
• 3a. Moon reflects light from the Sun.
• 3b. Moon’s revolution around Earth
causes phases.
What causes the moon’s phases?
• 4a. The moon rotates at the same rate it
revolves so from Earth we see different
amounts of the lighted side.
• 5. The moon rises 50 minutes later each
day because the Earth is revolving around
the sun at the same time the moon is
revolving around the Earth.
Phases of the moon handout
Sun: way
the heck to
the left
L
R
Full
L
New
Waning
Gibbous
R
Waning
Crescent
Last Half/
Last Quarter
Waxing
Crescent
Waxing
Gibbous
First Half/
First Quarter
•Notice the changing diameter of
the Moon during the 'moonth'. As
the Moon's orbit brings it closer to
earth (perigee) at the New Moon,
it appears larger to us.
•Also notice how the Moon 'rocks'
up and down and back and forth.
That happens because the
Moon's orbit takes it above the
Earth's equator (allowing us to
see more of the south polar
region) and below the equator
revealing more of the north polar
region of the Moon.
•The back and forth (east-west)
rocking is due to the changing
orbital velocity of the moon.
Resources
• http://images.google.com/imgres?imgurl=http://s
cienceworld.wolfram.com/astronomy/mimg90.gif
&imgrefurl=http://scienceworld.wolfram.com/astr
onomy/MoonPhase.html&h=293&w=496&sz=22
&hl=en&start=1&tbnid=BOoxosShoEBSqM:&tbn
h=77&tbnw=130&prev=/images%3Fq%3Dmoon
%2Bphases%26svnum%3D10%26hl%3Den%26
rls%3DHPIA,HPIA:200618,HPIA:en%26sa%3DN
• http://www.mrsciguy.com/resources.html
Eclipses and Tides
By Langley
Eclipses
• 1. Light of the Sun or Moon is blocked
• 2. Do not occur every month because the
Moon’s orbit and Earth’s orbit are in
different planes (5 degree difference)
Lunar Eclipse
• 3a. Moon Phase?
• 3b. Alignment?
Lunar Eclipses
•
2007 Mar
03Total1.23801h14mAmeric
as, Europe, Africa, Asia2007
Aug 28Total1.48101h31me
Asia, Aus., Pacific,
Americas2008 Feb
21Total1.11100h51mc
Pacific, Americas, Europe,
Africa2008 Aug
16Partial0.813-S. America,
Europe, Africa, Asia, Aus
• 3c. Frequency?
Solar Eclipse
• 4a. Moon Phase?
• 4b. Alignment?
Solar Eclipses
• 2005 Total Solar
Eclipse Path
• 4c. Frequency?
• Next one not until
after 2010.
Partner Discussion
• 5a. What are tides?
• 5b. What causes tides?
Tide Graph
• High to Low = ______ High to High = _______
• 5c. How much time between 2 high tides?
Effect of Sun and Moon on
Tides
Spring and Neap Tides
• 6a. Neap Tides:
Lower High Tide and
Higher Low Tide
• 6b. Moon phase
during neap tides?
• 7a. Spring Tides:
Higher High Tides
and Lower Low Tide
• 7b. Moon phase
during spring tides?
Spring Tide Alignment
8. Partner Discussion:
• A. Storm surge?
• B. When does
storm surge
occur?
• High Tides
• + Hurricane
• = Disaster
Resources
• http://www.pcssdweb.k12.ar.us/mills/images/lunar%20eclipse%202.j
pg
• http://science.nasa.gov/headlines/y2003/images/solareclipse/go1_m
ed.jpg
• http://www.hamilton.edu/images/storyimages/original_images/lunareclipse-10_27_041.jpg
• http://antwrp.gsfc.nasa.gov/apod/image/0007/nzeclipse_munford_bi
g.jpg
• http://www.salagram.net/solar-eclipse.gif
• http://www.coastal.edu/about/weather_plots/2_day_sm_tide.png
• http://www.sycsailors.com/wx/tide3.gif
• http://www.bom.gov.au/info/cyclone/storm_surge/images/stormsurge
_tide_smaller.jpg