ASTRONOMY: Earth and Space Systems

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ASTRONOMY Earth and Space Systems

• Standard 8-4.2
• Summarize the characteristics of the surface
  features of the Sun Photosphere, corona,
  sunspots, prominences, and solar flares.
• Standard 8-4.3
• Explain how the surface features of the Sun may
  affect Earth.
• 2/22/11

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LEARNING OBJECTIVE What are the characteristics
of the Sun that affect life on earth? Key
Questions What are the characteristics of the
sun? How does activity on the sun affect earth?
SUN - Gravity is by far the most powerful
force in the solar system. - Strong enough to
hold ALL of the planets and comets in orbit! -
Why is the gravity so strong? Because the suns
mass is very large! (Mass is the amount of
matter in an object) - 99.8 of the mass of
the solar system is in the sun.
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• Like Earth, Sun has an interior and exterior and
  an atmosphere.
• Unlike Earth, Sun does NOT have a solid surface.
  Sun is a ball of glowing gas.
• - ¾ of the suns mass is hydrogen, ¼ is helium
  and very small amounts are other chemical
  elements.

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SUNS INTERIOR

• Interior is like a giant furnace, sun
  produces its own energy.

HOW DOES THE SUN GET ITS ENERGY?
Suns energy comes from Nuclear FUSION
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SUNS INTERIOR
What is Fusion? Hydrogen atoms join (fuse)
together to form Helium. Nuclear fusion occurs
only under conditions of extremely high
temperatures and pressure.
- The temperature inside the suns core is about
15 million degrees Celsius, high enough for
nuclear fusion to occur. (Core center)
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SUNS ATMOSPHERE
Photosphere The inner layer of the suns
atmosphere. (photo - meaning light) When you
look at an image or photograph of the sun, you
are looking at the photosphere.
Chromosphere Middle layer of the suns
atmosphere. (Chromo meaning color)
Corona Outer layer of the suns atmosphere.
(Corona means crown in Latin).
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Photosphere
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Chromosphere
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Corona
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SUNS FEATURES

• Sunspots Are small dark areas on the suns
  surface.
• - Can be as large as Earth.
• Areas of gas on the sun that are cooler than the
  gases around them.
• Number of spots varies over a period of 10 or 11
  years.
• Hypothesized that short-term changes in climate
  on Earth may be related to sunspot cycles.

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SUNS FEATURES
Prominences Reddish loops of gas. These link
different parts of sunspot regions.
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Prominence
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• Solar wind The corona sends out a stream of
  electrically charged particles
• Earths magnetic field normally blocks these
  particles.
• Near North and South Poles, the particles enter
  the Earths atmosphere, where they hit gas
  molecules and cause them to glow.
• Solar wind can cause the Auroras (Northern
  Lights which are colorful display of dancing
  lights in the sky)

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• Solar flares Explosions
• - Areas in sunspot regions that suddenly connect,
  releasing large amounts of energy. The energy
  heats gas on the sun to millions of degrees
  Celsius, causing the hydrogen gas to explode out
  into space.
• Solar flares greatly increase the solar wind from
  the corona.
• This increases the amount of particles reaching
  Earth.

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Sun burst A picture taken by the Solar Dynamics
Observatory shows an exceptionally heavy plasma
eruption on the sun's surface on Sept. 8, 2010.
The eruption caused extreme ultraviolet
radiation, which did not hit the earth.
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It was a quiet day on the Sun in September of
2000. The above image from NASA's sun-observing
TRACE spacecraft shows, however, that even during
"off days" the Sun's surface is a busy place.
Shown in ultraviolet light, the relatively cool
dark regions have temperatures of thousands of
degrees. A large sunspot group is visible as
the bright area near the horizon. The bright
glowing gas flowing around the sunspots has a
temperature of over one million degrees Celsius
(1.8 million degrees Fahrenheit). The high
temperatures are thought to be related to the
rapidly changing magnetic field loops that
channel solar plasma.
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Sun Prominence This image was acquired from
NASA's Skylab space station on December 19, 1973.
It shows one of the most spectacular solar flares
ever recorded, propelled by magnetic forces,
lifting off from the Sun. It spans more than
588,000 km (365,000 miles) of the solar surface.
In this photograph, the solar poles are
distinguished by a relative absence of
supergranulation network, and a much darker tone
than the central portions of the disk. (Courtesy
NASA)
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Star Classification
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Life of a Star
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SC Standard 8-4.3 Explain how the surface
features of the Sun may affect Earth.
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SUNS AFFECT ON EARTH
What is the Solar Wind?
Where do these particles go?
What happens when they hit Earth and enter the
Earths atmosphere?
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SUNS AFFECT ON EARTH

• The Auroras Borealis (Northern Lights) are
  caused from these charged particles.

• Solar Flares and Prominences increase the
  particles in the solar wind that in turn affect
  Magnetic storms in Earths atmosphere.

• Magnetic storms often disrupt radio, telephone
  and television signals.

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LAB STORMY SUNSPOTS