Space Environment

1
Space Environment
Solar Physics
Sun
it is a star has a radius of about 696,000
km composed of H and He emits large amount of
mass and energy (about 4 x 10E33
erg/sec) quite sun radiates IR radiation
(thermal) Surface temperature (approximately
4,600 K) is about 93 miles away from the
Earth Also emits steady stream of protons and
electrons
H. Kirkici Istanbul Technical University
Lecture-4
September 30,2003
2
Space Environment
Solar Physics
Space environment and environmental effects in
Earth orbit are due to the solar activities
Sun releases energy in several forms Explosions
causes shock waves Magnetic field causes
disturbances Relative motion of the Earth, sun,
and other bodies causes local changes (i.e.
thermal)
H. Kirkici Istanbul Technical University
Lecture-4
September 30,2003
3
Space Environment
Solar Physics
Solar flare
The sun
The planets
Suns image during an eclipse
x-ray image
H. Kirkici Istanbul Technical University
Lecture-4
September 30,2003
4
Space Environment
Solar atmospheric layers
Chromospheres
Photosphere
Corona
H. Kirkici Istanbul Technical University
Lecture-4
September 30,2003
5
Space Environment
Photosphere, the visible surface of the Sun
H. Kirkici Istanbul Technical University
Lecture-4
September 30,2003
6
Space Environment
Chromospheres, the layer of the solar
atmosphere Located above the photosphere, but
beneath the transition region and the corona.
Hotter than photosphere, but not as hot as corona
H. Kirkici Istanbul Technical University
Lecture-4
September 30,2003
7
Space Environment
Corona
Outer layer of the solar atmosphere. Consists of
a highly rarefied gas with low density and a
high temperature.
Temperature is greater that 1,000,000 K. Visible
to the naked eye during the solar eclipse.
H. Kirkici Istanbul Technical University
Lecture-4
September 30,2003
8
Space Environment
Solar Physics and its influence on the formation
of the Earths atmosphere and near earth space
environments will be covered by Prof. Dr.
Yurdanur Tulunay
H. Kirkici Istanbul Technical University
Lecture-4
September 30,2003
9
Space Environment
Solar Spectrum
Electromagnetic Spectrum
Gamma rays 10E22 Hz Xrays 10E19
Hz UV VISIBLE 10E14 IR Microwaves 10E10
Hz RF 10E4 Hz Utility Power 50-60 Hz
irradiance
0.5 1.0 1.5 2.0
wavelength
UV
IR
visible
H. Kirkici Istanbul Technical University
Lecture-4
September 30,2003
10
Space Environment
Electromagnetic Spectrum Absorption and
transmission in Earths atmosphere
H. Kirkici Istanbul Technical University
Lecture-4
September 30,2003
11
Space Environment
Questions?...
H. Kirkici Istanbul Technical University
Lecture-4
September 30,2003