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Mrs
Gillum and the
Educator Astronaut
Program
CHAPTER 17: Section 1: A solar system is born: Student Copy
Questions: Try and answer these questions based on what you know:
1. What keeps the planets in their orbits?_________________________________
2. Why does the sun shine?___________________________________________
3. Why is the Earth round?___________________________________________
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Investigate Lab: Analysis 4
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Gravity, ____________________________________________________________,
is a universal force. The gravitational pull between two objects is strengthened by _____________
________________. Because of its mass, Earth holds us to its surface with a great gravitational force.
Our understanding of how the solar system formed and how it operates comes in part from our
knowledge of the opposing forces of gravity and pressure.
FYI: In space, the astronauts can “grow” 4-6 cm in height. Why??
_________________________________________________________________________
_________________________________________________________________________
Terms to know: (define these in as you learn them/or look them up tonight when you do the
reading & questions. Record in the vocab section)
solar system: (pg 424)_______________ Nebula: (pg 424) ______________
solar nebula (pg 425) _____________ planetesimal (pg 426) ______
Rotation (pg 429) _______________ Orbit (pg 429) ________________
Revolution (pg 429) _____________ period of revolution (pg 429) ____
Ellipse (pg 430) ________ astronomical unit (pg 430) ______
Questions: Could astronauts land on a star in the same way that they landed on the moon??
Why or why not?___________________________________________________________
________________________________________________________________________
Lecture:
Earth and 8 other planets orbit the sun. These 9 planets, (and their other bodies) and the sun are
part of the solar system, which is also referred to as a planetary system.A ________
_________ is composed of the sun (a star) and the other bodies that travel around the sun.
_________________________
Dust and gas clump together in _________________________________________
_________ which are so big it takes many years to cross them. These
nebulas are cold
(10 degrees above absolute zero) and dark. Over time, light from nearby stars
interacts with the
dust and gas allowing many new chemicals to be formed. Chemicals and bits of
complex molecules,
similar for the ones needed for life, are formed deep within the nebulas.
These clouds are the first ingredients of a new planetary system.
_______________________________________
These nebulas which consist of dust and gas _________________________,and
therefore
_________________________. Remember mass is a measure of the amount of matter
in an object
and is affected by the force of gravity. However, the matter in a nebula is
very spread out and
because of this the attraction between the gas/dust particles is very small.
__________________________________________________________________ _______________
_______________________________________ It is a measure of random molecular
motion, or vibration, of the particles in amaterial. This is not the same
as movement of the particles themselves. A cold gas or liquid can flow
at a fast rate, but it does not significantly affect the temperature of
the
fluid. If the gas molecules in a nebula move very slowly,
the temperature is very low and the cloud is cold. If they move fast, the
temperature is high and the cloud is warm. because the cloud has a temperature
that is above absolute zero, the gas molecules are moving. There is no particular
structure in the
cloud, and individual gas molecules can move in any direction, including crashing
into each other. These collisions create a push,or pressure, away from
the other gas particles.
________________________________ ________________ ____________________________________________________
The opposing forces of pressure & gravity reach a balance in a nebula
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The
force that pulls particles together (gravity) and
that which pushes them apart (pressure due
to the collision of particles) is illustrated on the left. Remember: the role of temperature in this system: As temperature increases, particles speed up, collisions increase, and pressure increases. |
_________________ is the force that pulls particles together and that which pushes them apart
__________ due to the collision of particles.Remember:the role of temperature in this system:
As temperature increases, particles speed up, collisions increase, and pressure increases.
The Solar Nebula Forms: Question:What keeps a nebula from collapsing?
Answer:__________________________________________________
Give an example where we can find this: students sitting in chairs. Gravity pulls them down
with a force equal to the force with which the chair pushes up.
Sometimes something can happen to upset this balance. When that happens nebulas can crash
into each other and stars can explode and areas can become so compressed that pressure can’t
react quickly enough to balance the gravity. When this happens the stage can be set for the
formation of a star, which in our case is the sun, and planets.______________ is the name of the
nebula that formed into our own solar system. Some of the complex molecules that are created in
these cold, dark clouds that eventually form stars and planets consist of fragments of amino acids
. _________________________________________________________
__________________Once our solar nebula started to collapse, things happened quickly
(based on a cosmic scale!) The dark clouds collapsed, matter in the clouds got closer and closer
together. The stronger attraction pulled the cloud together, and the gas and dust particles moved
at a faster rate, and the temperature increased in the cloud’s center. When the action in the center
of the solar nebula got real crowded, particles of dust and gas began to bump into other particles
more often. Eventually the dust and gas stopped moving in random directions and settled into a
slow rotation around the center of the cloud. The rotating solar nebula eventually flattened into a disk.
From Planetesimals to Planets
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|
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| Step1: the
young solar nebula begins to collapse due to gravity Step 2: the solar nebula begins to flatten and get warmer near its center Step 3: planetesimals begin to form within the swirling disc Step 4: because of their greater gravitational attraction, the largest planetesimals begin to sweep up more and more of the dust and gas of the nebula Step 5:Smaller planetesimals collide with the larger ones and planets begin to grow Step 6: The remaining dust and gas are gradually removed from the solar nebula, leaving planets around the sun- a new solar system. |
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As bits of dust within the nebula start to stick
together as they collide they begin to form
__________________________________________________called _________________________.
It takes about a 100,000 years but eventually these planetesimals
grow to the size of boulders and then eventually become the size
of a planet.
Planets:
__________________________________________________, were
all able to collect large
amounts of dust in the cooler, outer solar nebula. Once they grew large enough,
their gravity was
strong enough to attract the nebula gases, hydrogen and helium. Far from the
sun, it was cool enough
for the giant planets to collect ices in addition ot gases, Closer to the sun,
it was too hot for the gases
to remain, so these inner planets are made of rocky material.
So why are the giant gas planets so large??
__________________________________________________, where it
was cold and
there was more solid material (dust and ices) for the planets to collect.
What are the characteristics of the inner planets vs the outer planets??
_________________________rocky, small, thin atmosphere, few or no moons, molten
core in
Earth and Mars, dense__________________ mostly gas, huge, thick
atmosphere, many moons,
rocky core, not dense What caused these differences?? _________________________________
caused gases to burn away and allows only high-temperature solids, suck as
rock, to condense.
Birth of a Star In the middle of the solar nebula there is so much mass
and temperatures of 10 million degrees, that hydrogen fusion
begins.This creates so much pressure at the center that
the ____________________________________ |
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Planetary Motion: Rotation & Revolution How does the motion of the Earth cause day & night? This has to do with the earth spinning on its axis or ________Only 1/2 of the earth faces the sun at any given time.As the earth rotates, different parts of the Earth receive sunlight. ___________________________________ the half away from the sun has night. The Earth also travels around the sun in a path called an ____ This motion around the sun along ots orbit is called a ________. The other planets ALSO revolve around the sun.The amount of time it takes for a single trip around the sun is called a __________________________ The Earth revolves around the sun in 365 days.Mercury does this in 88. |
 Weird Science When you consider the motion of the Earth’s rotation, it’s revolution around the sun, and the sun’s movement around the Milky Way galaxy, you are actually traveling more than 900,000 km/h just standing still! |
Why are there seasons? Does the Earth get closer to the sun for summertime to occur????
NOOOOOOOOOOOOOOOOOOOO The placement of the Earth in orbit has NOTHING to do with
seasons_____________________________________________________ In the summer, the Northern Hemisphere is tilted toward the sun. In the winter, the Northern Hemisphere is tilted away from the sun. Earth is actually closest to the sun during the Northern hemisphere’s winter
| Quick Lab Take the cardboard, small piece of paper, string and 2 tacks.Pin both ends of the string down. Keeping the string stretched tight, use a pencil to trace out the path of an ellipse.Change the distance between the thumbtacks to change the shape of the ellipse. How does the position of the thumbtacks (foci) affect the ellipse? How did the position of the thumbtacks affect the ellipse? Answer: ________________________________ _________________________________________ |
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Kepler’s Laws of Motion:Johannes Kepler was
obsessed with trying to describe the geometric harmony
of the universe. He believed that there were 5 perfect geometric solids that
fit precisely between the 6 known planets and that this pattern contained
the divine meaning of the solar system. Through his efforts to prove this
idea, he discovered the elliptical orbit of the planets
Kepler’s First Law of Motion:Planets do not move
in a circle around the sun, but in an elongated circle
called an ellipse. The maximum length of an ellipse is its _________.
Half of this distance is the
_______________________. Distances are given in ______________________
or AU which represents the average semimajor axis distance between the Earth
and the sun
Newton’s law of Universal Gravitation:While
Kepler described the orbits of planets,
Sir Isaac newton showed WHY they orbit and WHY planets do not fly off into
space.
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Every object in the universe attracts every other with a force dependent on its mass and the square of the distance between them. |