Download Science of Sun activity

Science topics
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Magnetism
Sun spots
Solar flares
Corona mass ejections
Magnetism
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Magnetism is the force where objects
are attracted or repelled to one
another.
Magnets attract metals containing
iron, nickel, and/or cobalt but not
most other materials
Magnets have two poles where
magnetic strength is most powerful.
http://www.youtube.com/watch?v=uj0DFDfQajw
http://www.youtube.com/watch?v=HQdLFEiVeCA
Magnetism and EMR
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Keep in mind electricity is just
another form of electromagnetic
radiation
When a current (EMR) moves or
flows, it creates a magnetic field
Electric current is the source of
magnetism.
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Electric current is charge in motion &
anywhere there is an electric current
there is a magnetic force field
Anywhere there is charge there is an
electric force field present
If an object has no net electric
current flowing through it, there will
be no magnetic field
Magnetism
Bar Magnet with magnetic compasses placed around it. Note how the heads of
the compass needles point toward the magnetic south pole and away from the
magnetic north pole of the Bar Magnet.
(http://cse.ssl.berkeley.edu/SegwayEd/lessons/exploring_magnetism/Exploring_Magnetism/Exploring_Magnetism.pdf)
Magnetic Field line tracing of a bar magnet with a dipole magnetic
field using compasses.
Jump Rope Generator
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Jump Rope Generator worksheet
Sunspots
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Sunspots are places where strong
loops of the Sun’s magnetic fields
poke through the Sun’s surface
The magnetic fields trap plasma
inside and do not allow it outside the
loops, causing the area to be cooler
than average on the photosphere
and makes sunspots appear darker.
Scientists have found that sunspots are like magnetic poles of a bar
magnet. Draw what you predict the magnetic field above the surface of
the Sun looks like in the region around the sunspots.
Scientists have found that sunspots are like magnetic poles of a bar
magnet. Draw what you predict the magnetic field above the surface of
the Sun looks like in the region around the sunspots.
Sunspots and Coronal Loops
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Above the sunspots, the magnetic
field loop also traps hot plasmas =
coronal loops.
Sunspots
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Sunspots drift in position relative to one
another on the photosphere because of
convection beneath the photosphere plus
the differential rotation of the Sun.
These motions distort the sunspots’
magnetic fields and cause them to twist
up and become more and more
complicated in shape.
The more complicated the magnetic fields
shape become, the more energy they
store
Photosphere
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Visible surface of the Sun
about 100 km thick
Sun rotates on its axis once in
about 27 days - equatorial
regions rotate faster (about 24
days) than the polar regions
(rotate once in <30 days).
The Sun's rotation axis is tilted
by about 7.25 degrees from
the axis of the Earth's orbit so
we see more of the Sun's north
pole in September of each year
and more of its south pole in
March.
http://solarscience.msfc.nas
a.gov/images/sunturn.gif
Solar Flares
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Sudden, rapid, and intense increases
in brightness in relatively small
regions in the Sun’s atmosphere
Solar flares occur when magnetic
fields in the Sun’s atmosphere
rapidly change shape and generate
currents of electrically charged
plasmas.
Solar Flares
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The energy released by flares takes
the form of light, heat, and the
movement of large amounts of
plasma.
Light from across the entire
electromagnetic spectrum, from
radio waves to gamma rays, can be
generated in the biggest flares.
Solar Flares and CME’s
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Some flares also seem to generate
gigantic eruptions of matter that are
ejected out into interplanetary space
= Coronal Mass Ejections (or CME for
short).
Solar Flares and EMR
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Light is also produced in solar flares.
• Plasma consists of charged particles
• Plasma moves through magnetic field
associated with the sun
• When charged particles move through
a magnetic field they do not follow
straight paths but spiral around. This
spiraling motion is an acceleration that
causes the charged particles to radiate
light
Coronal mass ejections
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Powerful eruptions that can blow up
to 10 billion tons of the Sun's
atmosphere into interplanetary
space.
Traveling away from the Sun at
speeds of approximately one million
mph (1.6 million kph), CMEs can
create major disturbances in the
interplanetary medium and trigger
severe magnetic storms when they
collide with Earth's magnetosphere.
CME’s
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Large geomagnetic storms directed
towards Earth can damage and even
destroy satellites, are extremely
hazardous to Astronauts when
outside of the protection of the
Space Shuttle performing Extra
Vehicular Activities (EVAs), and they
have been known to cause electrical
power outages.
Space Weather
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Solar storm from the Sun travels through
space and impacts the Earth’s
magnetosphere.
Studying space weather is important to our
national economy because solar storms can
affect the advanced technology we have
become so dependent upon
Space Weather
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Energy and radiation from solar flares and
coronal mass ejections can:
• Harm astronauts in space
• Damage sensitive electronics on orbiting
spacecraft…
• Cause colorful auroras, often seen in the
higher latitudes…
• Create blackouts on Earth when they
cause surges in power grids.
Solar Wind
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The solar wind speed is not uniform
Always directed away from the Sun
Solar wind speed is 800 km/s over
coronal holes and low (300 km/s)
over streamers.
High and low speed streams interact
with each other and pass by the
Earth as the Sun rotates and can
produce storms in the Earth's
magnetosphere.
Solar wind
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The solar wind consists of particles,
ionized atoms from the solar corona,
and fields, in particular magnetic
fields.
As the Sun rotates the magnetic field
transported by the solar wind gets
wrapped into a spiral
Variations in the Sun's magnetic field
are carried outward by the solar wind
Solar wind
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Solar wind streams off of the Sun in all
directions at speeds of about 400 km/s
(about 1 million miles per hour).
Source of the solar wind is the Sun's
corona where the temperature is so high
that the Sun's gravity cannot hold on to it.
We do not understand the details about
how and where the coronal gases are
accelerated to these high velocities.
Magnetosphere
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Solar wind and its magnet field, is
strong enough to interact with the
planets and their magnetic fields to
shape magnetospheres
A magnetosphere is the region
surrounding a planet where the
planet's magnetic field dominates
Magnetosphere protects life on
Earth
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Because ions in the solar plasma
(wind)are charged
• They interact with these magnetic fields
• Solar wind particles are swept around
planetary magnetospheres.
• Life on Earth has developed under the
protection of this magnetosphere.
Shape of Earth’s
Magnetosphere
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Solar wind compresses its
sunward side to a distance of
6 to 10 times the radius of the
Earth.
A shock wave is created
sunward of Earth like a sonic
boom – called the bow
shock.
Most of the solar wind
particles are heated and
slowed at the bow shock and
detour around the Earth.
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Solar wind drags out the
night-side magnetosphere to
possibly 1000 times Earth's
radius (exact length unknow)
This extension of the
magnetosphere is known as
the magnetotail. Many other
planets in our solar system
have magnetospheres of
similar, solar wind-influenced
shapes.
Earth’s Magnetosphere
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Magnetosphere is dynamic and
fluctuates with time
http://pixie.spasci.com/DynMod/movie20000714.gif
Magnetism in space
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In space there is no magnetic iron,
yet magnetism is widespread.
Sunspots consist of glowing hot gas,
yet they are all intensely magnetic.
The Earth's own magnetic powers
arise deep in its interior, and
temperatures there are too high for
iron magnets
It is all related to electricity
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Remember: anywhere there is an
electric current there is a magnetic
force field and anywhere there is
charge there is an electric force field
present
So movement of sunspots with
plasma and CME’s will pass through
magnetic fields and produce electric
fields
On the left, a model of the
magnetic field (spiral lines) of the
Sun (in the middle) is shown as
one looks down on the Sun’s axis
of rotation. This magnetic field is
known as the interplanetary
magnetic field (IMF). The orbits of
Mercury, Venus, and Earth are
shown as circles. The spiral of the
IMF shown here is due to the fact
that the IMF is attached to the
rotating Sun, but we draw it from
a non-rotating perspective from
above.