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The
Earth's magnetic field interacts with solar emissions
in
a region
called the magnetosphere.
Magnetosphere
The
ionosphere
is
the upper atmosphere in space that extends from
roughly 80 km to about 1000 km. Neutral gas atoms
and molecules are ionized here by solar radiation
creating ionized gas. Spacecraft design must take
into account the ionosphere's substantial radio
wave propagation, charging and chemical effects.
Solar
wind is a very hot plasma (ionized
gas) that flows from the Sun into interplanetary
space at less than the speed of light, 300 to 800
km/s. Solar wind impacting the magnetosphere gives
it the shape of a comet. This impact point is called
the bow shock.
The
magnetosphere
is a vast comet-shaped
region that lies above the ionosphere and extends
over 10 Earth radii (Earth's radius ~ 6378 km) towards
interplanetary space. Within this cavity exists
a low-density population of high-energy particles.
Areas of similar particle and electromagnetic characteristics
are divided into sub-regions. One of these is the
Van Allen belts, where the radiation rapidly degrades
satellite solar arrays.
Radiation
in
space consists of highly energetic (tens of keV
to hundreds of MeV) ions and electrons found in
the magnetosphere field and solar flares. Interplanetary
radiation includes solar ultraviolet and X-ray fluxes.
Humans are endangered by these types of radiation;
it is also harmful to spacecraft electronics and
solar cells.
