Transcript The Sun : Our Closest Star

The Sun : Our Closest Star
A. The Size of The Sun
1. The sun is a medium size star.
 99 % of ALL matter in our solar system is
in the sun.
 It is about 93 million miles from the Earth
or 150 million kilometers.
 It takes 7.8 min. for light to get to Earth.
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A. The Size of the Sun
The diameter of the sun is 864,000 miles
( 1. 39 million kilometers)
Earth is 12,104 km in diameter ( the sun is
116 x BIGGER ! ) ( Earth =7,747 miles)
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B. The Sun has LAYERS
From the inside out: ( see p 679 )
 Core
 Radiation Zone
 Convection Zone
 Photosphere
 Chromosphere
 Corona
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B. Continued…Layers
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1. Light comes from the Photosphere
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2. The Corona is thousands of miles thick.
It’s temperature = 2,000,000 degrees C
The temperature of the core is
15,000,000 Degrees C.
B. The Sun has Layers:
C. Surface Features of The Sun
Solar Flares
 Prominences
 Sun Spots
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C. Surface Features of the Sun
1. Solar Flares = violent gas eruptions
a. They cause damage to satellites,
b. interfere with radio & T.V.,
c. and cause Aurora Borealis ( the Northern
Lights). The Norse myth of the Valkaries
Is connected to this.
a. Gov. Web
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C. Surface Features of the Sun
2. Prominences = huge columns of gas
that fly out from the sun.
 They are thousands of miles long.
 UV & X-rays increase.
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Web
Prominences are HUGE
C. Surface Features…
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a.
b.
c.
Sun Spots = Dark areas that are cooler
parts on the sun’s surface.
This shows that the sun ROTATES.
Spots are not permanent. They last from
days to months.
The “sun spot maxima” occurs every 11
years.
D. Nuclear Fusion Occurs in the
Sun’s Core
Hydrogen atoms join to become Helium
atoms.
 This is a nuclear reaction ( not a chemical
reaction. Chemical reactions involve
electrons.)
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Video
E. NASA’s Tools For Studying
the Sun
Solar Probes
 SOHO Space Observatory (1.5 million km
above Earth)
The primary scientific aims of the Solar and
Heliospheric Observatory mission (SOHO)
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