The Sun interacts with the Earth through
Electromagnetic Radiation
and
The Solar Wind
Image courtesy of National Aeronautics and Space Administration
(NASA)
Electromagnetic Radiation
ƒTravels at the speed of light, 300,000 km/s
(186,000 mi/s)
ƒTakes approximately 8 minutes to reach the
Earth
Image courtesy of Occupational Safety & Health Administration
(OSHA)
The Solar Wind
„
Consists of charged
particles (protons and
electrons)
„
Takes several days to
reach the earth
„
Average density is 510 particles per cubic
centimeter
Courtesy of SOHO/EIT consortium. SOHO is a project of
international cooperation between ESA and NASA
Sun Structure
Image courtesy of National Aeronautics and Space
Administration (NASA)
The Core
„
It’s HOT!!!! 15
Million degrees
Kelvin
„
It’s DENSE!!!! 10
times more dense
than lead
And……
Image courtesy of Tungsten Heavy Powder,
Inc.
Fusion
„
At that temperature
and density, nuclear
fusion occurs
„
Fusion is the source
of the sun’s
electromagnetic
radiation
Image courtesy of the Lawrence Berkeley National Laboratory
Did You Know?
The sun converts
5 million tons
of matter into
energy every
second.
Radiative Zone
„
Energy is
transported from
the core through
radiation
„
Energy is
constantly
absorbed and reemitted by atoms
Courtesy of SOHO/EIT consortium. SOHO is a project of
international cooperation between ESA and NASA
It’s a LONG Road
„
It takes thousands to
millions of years for
the energy released by
the fusion process to
reach the sun’s
convective zone
Image credit Yohkoh Public Outreach Project
Convective Zone
„
Energy transfer is
similar to motion of
boiling water in a pot
„
Hot interior gases
move outward as
cooler gases sink
Image courtesy of the Alder Planetarium
PHOTOSPHERE
ƒLayer of the Sun
we see
ƒVisible sunspots
ƒExhibits
granulation
Image courtesy of Space Science News
Solar Granules
„
Visible proof of
convection zone
„
Masses of hot gas that
rise and fall
„
Each granule is about
the size of an earth
continent
Image courtesy of National Aeronautics and Space
Administration (NASA)
Corona
ƒSun’s outer
atmosphere
ƒTemperature
rises to millions of
degrees K
ƒExtends millions
of kilometers into
space
Image courtesy of National Aeronautics and Space
Administration (NASA)
Did You Know?
The Sun’s corona
or atmosphere is
hundreds of times
hotter than its
surface
Image courtesy of National Aeronautics and Space
Administration (NASA)
Solar Events
„
Sun spots
„
Solar flares
„
Coronal mass
ejections (CME’s)
Courtesy of SOHO/EIT consortium. SOHO is a project of
international cooperation between ESA and NASA
Sun Spots
„
Cool areas of the
photosphere
„
Number varies in
approximate 11 year
solar cycle
„
Produced by local
solar magnetic fields
Size of Earth
Courtesy of SOHO/MDI consortium. SOHO is a project of
international cooperation between ESA and NASA
Solar Flares
„
Most occur in and
around sun spots
„
Frequency follows
solar cycle
„
Source of dangerous
levels of radiation
solar flare
Courtesy of SOHO/EIT consortium. SOHO is a project of
international cooperation between ESA and NASA
Coronal Mass Ejection (CME)
„
Eruption of large
bubble of solar
material
„
Creates the most
adverse effect on
Earth’s
magnetosphere
Courtesy of SOHO/LASCO consortium. SOHO is a project of
international cooperation between ESA and NASA
The Structure of the Earth
Two main components of
the earth system affected
by solar activity are:
ƒThe earth’s
ionosphere (upper
atmosphere)
ƒThe earth’s magnetic
field, called the
magnetosphere
Image credit – The Canadian Space Agency http://www.space.gc.ca/
Image courtesy of National Aeronautics and Space
Administration (NASA)
The Ionosphere
„
Far above the area in
which we live
„
Layer of the earth's
atmosphere that is
ionized by solar radiation
„
Plays a significant role in
radio, television, and
satellite communications
Courtesy of Windows to the Universe, http://www.windows.ucar.edu
The Magnetosphere
„
Area of space around the
Earth that is controlled by
the Earth's magnetic field
„
Shape is the direct result
of being blasted by solar
wind
„
Protects us from most of
the harmful effects of
space weather
Image courtesy of National Aeronautics and Space
Administration (NASA)
Space Weather
„
The condition of the
space environment
influenced by the sun
„
Earth consequences
can be beautiful but
disruptive
Image courtesy of Stanford Solar Center
Aurora Borealis
„
Also known as the
northern lights
„
Solar wind excites
gases in the
ionosphere
„
Most common sign
of space weather
activity
Image courtesy of National Aeronautics and Space
Administration (NASA)
Did You Know?
During a major
solar storm,
auroras can be
seen as far south
as Florida, Texas,
and even Mexico.
Image courtesy of National Aeronautics and Space
Administration (NASA)
Satellite, communications, and
power disturbances
Image courtesy of National Aeronautics and Space Administration (NASA)