The Sun and its Effect on Earth

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The Sun and its Effect on Earth
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Course Vitals

• Date/time Wednesday 900-950AM
• Goal/Motivation
• To delve into more detail about the Sun, how it
  changes, and how it effects Earth and its
  inhabitants, than in a broader gen-ed course.
• This will be a discussion-driven class!
• I will lecture 15-20 minutes each day, the rest
  of the period will be devoted to discussion.
• Lets see where the topics go!
• No math but we will discuss science.

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Course Vitals (cont.)

• Grading
• 40 participation
• 30 writing assignment
• 30 in-class presentation (8-10 minutes)
• Course home page
• www.lpl.arizona.edu/undergrad/classes/fall2006/Gia
  calone_195A
• (see this page for a tentative list of topics)
• Instructor office hours after class, or just
  stop by (431 Kuiper Space Sciences)

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General outline of the course

• How does the Sun effect Earth?
• Does the Sun change? How?
• How does the changing Sun effect Earth?
• What is space radiation and how does it affect
  humans in space?

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An x-ray image of the Sun (SoHO)
The largest flare seen since the National Oceanic
and Atmospheric Administration (NOAA) began
recording them in 1976
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A Fact About Huge Solar Flares (slightly smaller
ones occur, on average, about 3 times per day
during solar max)
Artists depiction of a large asteroid striking
the Earth (which occur, on average, about 1 every
100 million years)
Asteroid Energy 5x1030 ergs 100 times less than
a flare!
Flare Energy 5x1032 ergs
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The Sun seen from space
SOHO/LASCO (C3) movie of the Halloween Solar
Storms of 2003
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Why Study the Sun ?

• Influence on Earth
• Important for Astronomy/Planetary Sciences
• Only star that we can see closely
• The source of many interesting and important
  physics problems
• Many interesting research projects
• For me?
• Many basic properties are a mystery
• Understanding the space radiation environment,
  space weather, cosmic rays

Inti, The Inca Sun God
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What does the Sun Look like from Earth?
Photosphere as seen with a Mylar filter
Chromosphere as seen using an Ha filter
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SOLAR CORONA SEEN DURING A TOTAL ECLIPSE
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The Sun seen in x-rays
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Close up of the Sun seen by the spacecraft
Hinode
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Close-up images of the solar surface and a
sunspot with Earth as a scale
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The Sunspot Cycle
Number of Sunspots versus time they come and go
every 11 years
Lots of sunspots ? Solar Maximum
lots of solar
activity Few sunspots ? Solar Minimum
quiet Sun
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Reading For Next Week

• Further discussion of the Sun
• What is the structure of the Sun?
• What is the solar constant?
• What are the consequences on Earth of incoming
  solar energy?
• Be prepared to get involved in the discussion
  about these topics
• A few useful internet links will be posted on the
  course website this afternoon. You should read
  the information on these sites before next class.