Transcript Astronomy - Ascent Academies of Utah Blogging System Sites

Astronomy
The Solar System
What you need to know
• How do the heliocentric and geocentric
models of the solar system differ?
• Describe what Kepler discovered about the
orbits of the planets.
• Identify two factors that keep the planets in
their orbits.
Word Attack
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geocentric
heliocentric
ellipse
inertia
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fusion
photosphere
chromosphere
nuclear
Heliocentric v. Geocentric
• Heliocentric Model
 Earth and the other
planets revolve around
the sun
 Nicolaus Copernicus
 early 1500s
• Geocentric Model
 Earth is at the center
of the revolving planets
 Ptolemy (TAHL uh mee)
 A.D. 140
The Sun
• The Sun’s Interior
• extremely high temperature + extremely high
pressure
• hydrogen atoms fuse to form helium
• nuclear fusion
• temperature in the core reaches 15 million degrees
Celsius
Interior of the Sun
The Sun
• The Sun’s Atmosphere
• photosphere - inner layer (creates the light)
• chromosphere - middle layer (reddish glow)
• corona - outer layer (visible during total eclipse)
The Sun’s Atmosphere
The Sun
• Features of the Sun
• sunspots - areas of gas that are cooler than the
areas around them; many are as large as Earth or
larger
• prominences - reddish loops of gas linking sunspot
regions
• solar flares - hydrogen gas explosions
• solar wind - increased by solar flares; can cause
magnetic storms in Earth’s upper atmosphere
disrupting radio, telephone, and television signals.
The Sun Now
Sunspots
Sun Prominences
Solar Flares
Solar Wind
The Inner Planets
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Mercury
Venus
Earth
Mars
Mercury
• closest to sun
• 450°C during the day
• -170°C at night
Mercury
Astronomy Textbooks
• Open your textbook to page 64
• Find 5 (five) more facts about Mercury
• Write the 5 facts on your note page next to
the slides about Mercury
• You have 5 minutes to read and write
Venus
• known as the “evening star” Venus can be seen
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in the west after sunset and again as the
“morning star” just before sunrise
“day” is longer than “year” - 7.5 Earth months to
revolve around the sun; 8 Earth months to rotate
on its axis
Retrograde rotation (rotating East to West,
opposite of most planets and moons)
Atmosphere contains sulfuric acid and carbon
dioxide
Venus
Astronomy Textbooks
• Open your textbook to page 65-66
• Find 5 (five) more facts about Venus
• Write the 5 facts on your note page next to
the slides about Venus
• You have 5 minutes to read and write
Earth
Astronomy Textbooks
• Open your textbook to pages 62-63
• Find 5 (five) more facts about Earth
• Write the 5 facts on your note page next to
the slides about Earth
• You have 5 minutes to read and write
Mars
• the “red planet”
• polar ice cap at north pole contains water
• polar ice cap at south pole is frozen carbon
dioxide
Mars
Astronomy Textbooks
• Open your textbook to pages 67-69
• Find 5 (five) more facts about Mars
• Write the 5 facts on your note page next to
the slides about Mars
• You have 5 minutes to read and write
end of Part 1
• When your notes are completed, please
work on the worksheet “The Inner Planets”.
• Please complete the worksheet during
your study time after school if it is not
finished when you leave class.
• Thank you for participating in our science
lesson today.
• Have a great day! :)
Vocabulary
• terrestrial planet
• retrograde motion
• greenhouse effect
Inner v. Outer Planets
• Inner Planets
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4 (four)
small
rocky surfaces
terrestrial planets
• Outer Planets
 4 (four)
 much larger than Earth
 do NOT have solid
surfaces
 gas giants
Outer Planets (aka Gas Giants)
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Jupiter
Saturn
Uranus
Neptune
Jupiter
• atmosphere of hydrogen and helium
• “The Great Red Spot” is a storm like a
hurricane
• 17 moons
Jupiter
Astronomy Textbook
• Turn to page 72 -73
• Find 3 facts about Jupiter
• Add these facts to your note pages
Saturn
• second largest planet in the solar system
• chunks of ice and rock orbit in rings
• 5 moons
Saturn
Astronomy Textbook
• Turn to page 73 - 74
• Find 3 facts about Saturn
• Add these facts to your note pages
Uranus
• atmosphere contains traces of methane
• Voyager 2 provided the only photographs
we have
• 17 moons
Uranus
Uranus with shadow of eclipse
Astronomy Textbook
• Turn to page 75
• Find 3 facts about Uranus
• Add these facts to your note pages
Neptune
• 30 times Earth’s distance from the sun
• 8 moons have been discovered
Neptune
Astronomy Textbook
• Turn to page 76
• Find 3 facts about Neptune
• Add these facts to your note pages
Outer Planets
• are MUCH larger than inner planets
• have a stronger gravitational force than
inner planets and keeps gases from
escaping their atmospheres
• may have a partly solid core made of rock,
ice, frozen carbon dioxide, and other
compounds
Ceres, Pluto, & Eris
• Dwarf Planets - Pluto and any other round
object that "has not cleared the
neighborhood around its orbit, and is not a
satellite.”
Identified Dwarf Planets
Ceres
Pluto
Eris (2003 UB313)
Comets
• A comet has a distinct center called a nucleus. Most
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astronomers think the nucleus is made of frozen water
and gases mixed with dust and rocky material.
Comet nuclei are described as dirty snowballs.
A hazy cloud called a coma surrounds the nucleus.
The coma and the nucleus together form the comet's
head.
Comets
• Scientists think that about 100 million comets orbit the Sun.
• The name comet comes from the Latin word cometa which means
"long-haired".
• The earliest known record of a comet sighting was made by an
astrologer of the Chinese court in 1059 B.C.
• Comets are thought to originate from the Kuiper Belt and beyond.
Asteroids
• Most asteroids revolve around the sun between the orbits
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of Mars and Jupiter in the Asteroid Belt
The asteroid belt separates the inner planets from the
outer planets
Meteors
• Meteors are bits of space debris falling through
Earth's atmosphere
Kuiper Belt
• The Kuiper Belt is often called our Solar System's 'final
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frontier.' This disk-shaped region of icy debris is about 4.5
to 7.5 billion km (2.8 billion to 4.6 billion miles), 30 to 50
Astronomical Units (AU) from our Sun.
Its existence confirmed only a decade ago, the Kuiper
Belt and its collection of icy objects - Kuiper Belt Objects
(KBOs) - are an emerging area of research in planetary
science.
No spacecraft has ever traveled to the Kuiper Belt, but
NASA's New Horizons mission, planned to arrive at Pluto
in 2015, might be able to penetrate farther into the Kuiper
Belt to study one of these mysterious objects.
Where’s the Kuiper Belt?
So what holds our Solar
System together?
• Gravity
 the attractive force between two objects
 its magnitude depends on their masses and
the distance between them (32)
• Inertia
 the tendency of a moving object to continue in
a straight line or a stationary object to remain
in place (53)
Gravity
• The easiest way to think of gravity is that
it's the thing that makes you stick to the
Earth. It's like a giant hand that reaches up
from the ground, grabs your ankle and
holds you down. Gravity affects the amount
of force that you exert on the ground. It's
like you are pushing on the ground!
You and the earth
Now that you know what gravity is, we can
tell you what weight and mass are...
• Mass is just the amount of "stuff" you are made
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of! No matter where you go in the Universe, you
are still made of the same amount of stuff, so
your mass is always the same. (Unless, of
course, you grow. Then your mass increases.)
The force of gravity that you push on the ground
with is called weight. You might weigh 66 pounds
on the Earth... But you would weigh 1/6 of this on
the moon (only 11 pounds) because the moon's
gravity is 1/6 as strong as the Earths.
How much do you weigh on
other planets?
• To find out how much you might weigh on
other planets, visit
www.sciencemonster.com
"The First Law of Motion!"
• If something is moving, it will keep moving
until something stops it. If something is not
moving, it will just sit there until something
comes along to move it.
• Here is the official, scientific way to say it:
 An object in motion will continue to stay in
motion unless acted upon by an outside force.
An object at rest will continue to stay at rest
unless acted upon by an outside force.
Here's a good example:
• Picture yourself racing down the sidewalk on your blades.
If you pushed off just once and coasted, how long would
it take you to stop? Would you stop a lot faster if you
were on asphalt instead of smooth cement? You sure
would! That's because there's a lot more friction to slow
you down on the asphalt.
• Now, what if you were using ice skates on ice? It would
be nice and smooth - less friction - and you'd coast a lot
longer right?
Well, there's no friction in space...
• If you were coasting out in space, there'd be nothing to
stop you and you'd just keep drifting! Unless something
like a comet came along and stopped you. Get the idea?
That's inertia!
• What if you put a book on a table... It would just sit there
unless you moved it. You could pick it up... or push it... or
lift one side of the table so it would side off.
That's inertia!
What does this mean for our
Solar System?
• Gravity pulls the planets and other objects
toward the sun and each other
• Inertia keeps them traveling along their
path
So…
• a planet or object in orbit around the sun or
another object will continue along that orbit
until another object pushes it or pulls it out
of orbit
• an object shooting through space will
continue until another object stops it
Well, that’s it folks!
• We’ll study the stars and constellations
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next!
Here’s a sneak peak --
Bibliography
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courses.nnu.edu/.../images/Interior_of_sun.jpg
personal.tcu.edu
space.newscientist.com
open2.net/.../208587/carbon_hst_venus95.jpg
astrobiology.nasa.gov
astronomy-for-kidsonline.com/.../meteor.jpg
en.wikibooks.org
sohowww.nascom.nasa.gov/
sti.nasa.gov/
spa3.k12.sc.us
somewhereville.com/gnw/tas/pluto.jpg
cnes.fr
sciencemonster.com/gravity_inertia.html
astropix.com/HTML/C_SPRING/BIGDIP.HTM
American Preparatory Academy
• ©2008