Sun and Moon
The Sun is….
• A star
• In the Main Sequence stage
• 99% of the total mass in the solar system
• 109 times as big as the Earth
Energy Production in the Sun
• Nuclear fusion occurs in the sun to give it
its energy.
• Hydrogen is converted into Helium.
Structure of the Sun
• The sun does not have a solid surface.
The visible surface is where its
atmosphere becomes so thick that you
can’t see through it.
• The sun is divided into 6 layers.
Layers
of the
sun
Layers of the Sun
• Corona- Outermost part of the sun’s
atmosphere. Visible only during a solar
eclipse
• Chromosphere- section of the sun’s
atmosphere below the corona.
• Photosphere- the visible part of the sun’s
atmosphere. The “surface” we see.
• Convective Zone- Section where
convection currents carry energy to the outer
atmosphere of the sun
Layers of the Sun Continued...
• Radiative Zone- Very dense section of
the sun where energy is trapped.
• Core- inner part of the sun where the
sun’s energy is produced by nuclear
fusion.
What Layer is
shown here?
Hint:
Solar Eclipse
Solar Activity
• The circulation of energy causes gas in the
photosphere to churn, causing magnetic
fields that reach into space.
– Sunspots- when the activity slows down in one
spot, and the photosphere becomes cooler than
other areas. Sunspots are cooler, dark spots
on the sun.
• Sunspots change in a regular pattern. About every 11
years there is a peak in sunspots.
They might affect
our climate and cause lower temperatures on earth.
Sunspots
Solar Activity continued...
• Solar Flares- regions of extremely high
temperatures and brightness that develop on
the sun’s surface. When they erupt, they send
streams of electrically charged particles into the
solar system.
– They can extend several thousand miles into
space within minutes.
– Particles from solar flares reach earth and interrupt
radio and cell signals.
Solar Flare
Aurora Borealis
Northern Lights
• When solar particles enter our atmosphere, they are
attracted to the poles, and cause Aurora
Borealis
Formation of the Moon
• Three explanations for how the moon
could have formed:
– Twin Theory
– Meteor Theory
– Capture Theory
Twin Theory
• The moon formed at the same time as Earth.
– Gravity pulled particles in the solar system together
to make the earth and the moon out of a nebula
Meteor Theory
• When Earth was first cooling, a meteor
struck it and “splashed” a piece off
which hardened to form the moon.
Capture Theory
• The Moon formed someplace else, it flew
by Earth and gravity captured it into
orbit.
Features of the Moon
• Maria- smooth
dark plains on
the moon
• Highlandsrugged
mountains on
the moon that
appear as light
places.
Features of the Moon
• Rilles- lines
on the moon
where the crust
of the moon
cracked when it
cooled.
• Craters- round
impacts from
meteors
Why are there so many craters
on the moon?
• The moon has no
ATMOSPHERE, so
it has no
WEATHER, so
there is no
EROSION.
• Therefore, when the
moon gets struck by
a meteor, the crater
stays there forever.
Label
each
section
#1- #9