Science 9
Section 11.1 Notes
1
Section 11.1
The Sun and its Effect on Earth
(Text Pages 390 – 397)
Key Terms:
Solar Prominences
Solar Wind
Solar Flares
Solar Radiation
Sunspots
Section 11.1 Learning Objectives:
 Describe the characteristics of the sun. Include the following features:
o Sun spots
o Solar flares
o Solar prominences
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The Sun
 What do each of the following items pictured below have in common?
 They all exist because of the sun’s energy!
Sun Summary Chart
Criteria
Mass
Motion
Composition
Function
Characteristics
Science 9
Section 11.1 Notes
2
Special Features of the Sun
 Our sun is only an average sized star, but it is still 300 000 times more massive than the earth! In
fact, it has 99% of the mass in our solar system. This means that if you packed all of the planets into
one giant planet, the sun would still be about 100 times larger!
 Solar radiation emitted from the sun is what provides the energy needed for life to exist on earth.
The earth’s atmosphere protects life from the harmful effects of this radiation. Without the
atmosphere, specifically the ozone layer, we would not survive.
Figure 11.3 from Text Page 392
 The sun may appear the same from earth, but it is an amazingly dynamic (changes often) system.
 Several special features can be observed with technology or, if you are lucky, during a total solar
eclipse (when the moon passes in front of the sun.) These include:
o
Sun Spots
o
Solar Flares
o
Solar Prominences
Science 9
Section 11.1 Notes
3
Sun Spots:
 The dark patches on the sun are known as sun spots. Some can be larger than
the width of ____________________.
 They are parts of the surface that are ______________ (about_________) than
other parts of the sun.
 The number of sunspots increases and decreases on an _________________
____________________________.
 More sun spots means the sun is more active!
Solar Prominences:
 Solar Prominences are ______________________________________ that
extend out from the sun’s surface. They are associated with sun spot activity.
 They can travel a very great distance from the surface of the sun,
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Solar Flares:
 Similar to solar prominences but much hotter. These extremely violent
eruptions last for ______________ and release vast amounts of
________________________________.
 The gas in these eruptions is nearly ________________________
_______________!
Solar Wind
 When solar flares or other solar eruptions occur, they can eject large amounts of _____________
_______________ into space.
 As these high energy particles rush past earth they create _______________________. Without the
protection of the earth’s ____________________, these solar winds would be ______________ for
the organisms on earth.
 These winds have a significant effect on our planet:
o
At the north and south poles they cause the ______________ (aurora borealis in the north!)
o
Strong solar winds can interfere with ________________ and damage ________________
on earth.
o
They are a threat to _____________________. Without specially shielded capsules they
would be in great danger from the vast amounts of __________________.
Science 9
Section 11.1 Notes
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Science 9
Section 11.1 Notes
5
Worksheet 11-1
1) What does earth have that protects it from solar radiation? Do you know if it is possible for people
to damage this protective layer?
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2) Draw sketches to show the difference between a solar flare and a solar prominence. Label each
sketch.
3) Your notes suggest that the sun is dynamic, meaning it changes frequently. What do you know
about the sun that supports this idea?
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4) Draw a small cartoon to demonstrate one or more effects of solar radiation on the earth.
Science 9
Section 11.1 Notes
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Use the text pages 390 – 394 to answer the following questions:
5) About how old is the sun and how long do scientists think it will keep burning?
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6) Why do astronomers refer to Earth as being in the ‘goldilocks zone’ of the sun?
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7) How might sun spots be related to our climate on earth? What time period do they normally cycle
on?
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8) Why would it be beneficial to be able to predict increases in solar winds or solar storms?
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